When you warp to an asteroid belt, you will land in the middle of a semicircle of asteroids about 50 km in diameter. Since the (unboosted) range of mining lasers is only 10 km (15 km for strip miners), you will then need to fly closer to your target asteroid in order to mine it - and mining ships are not particularly known for their speed. You can cut down on this travel time by using bookmarks, which allow you to warp directly next to an asteroid, and start mining immediately. If you're using mining drones, it's particularly important to be close to your target asteroid, as the drones have to otherwise spend a lot of time travelling back and forth between your ship and the asteroid.
It can be helpful to create bookmarks in the asteroid belts you mine in frequently. While there are many different approaches to creating these bookmarks, the picture on the right shows a simple example: warp to an asteroid belt in a fast ship (e.g. a shuttle or a frigate), and create three bookmarks along the perimeter of the belt. Position them in such a way that most of the belt is within 15 km (the range of a strip miner) of any of the three bookmarks. Then, switch to your mining ship, and warp directly to one of the three bookmarks. You will then have a large selection of asteroids within range of your lasers, and be able to efficiently use mining drones on the closest ones. If a part of the belt is depleted, warp to a nearby celestial (e.g. a planet) and then warp back to one of the other bookmarks in the belt.
The survey scanner (a mid-slot module) is a very useful tool for any asteroid miner, as it shows how much ore each asteroid in the vicinity contains. This is important, as asteroid mining modules (mining lasers and strip miners) will always complete an entire cycle (60s for mining lasers, 180s for strip miners), irrespective of how much ore is actually left in the asteroid.
For instance, say you are mining an asteroid which contains 200 units of Veldspar (Veldspar has a volume of 0.1 m3 per unit, so this asteroid contains 20 m3 of Veldspar). Your Mining Laser I has a yield of (say) 100 m3/min, and a cycle time of 60 seconds. Even though there are only 20 m3 of Veldspar left in the asteroid, the module will complete its entire 60 second cycle before shutting off (with a message saying “the asteroid is depleted”) - but those 60 seconds of mining only yielded 20 m3 of ore (instead 100 m3)! The problem becomes even worse when using strip miners, as they have a much higher yield and a cycle time three times as long - which can result in a lot of wasted time if you're mining asteroids that don't contain much ore.
Therefore, when mining, refresh the survey scanner window from time to time (it does not refresh automatically, you need to reactivate the survey scanner module) to check whether the asteroid(s) you are mining are close to depletion. If an asteroid is almost empty, you can “short-cycle” your mining laser (i.e. turn it off manually before it completes its full cycle, by clicking on it) to mine out the last dregs of ore before moving on to another asteroid. Note that each time you activate your mining laser it takes energy from your ship's capacitor; activate it too often and you might empty your capacitor and have to wait a moment for it to recharge.
You can target asteroids directly from the survey scanner window (much like the asteroids in the overview); this can be a useful shortcut to help you mine the particular asteroid you're interested in. A little marker shows you which asteroids you are targeting (note that, just like the rest of the information, this is only refreshed when you refresh the survey scanner window).
Survey scanners can be used to provide the approximate value of an asteroid belt with the help of 3rd party appraisal tools. This activity is relatively easy when in a fleet that provides range bonuses to Survey Scanner. Without range boosts an estimate can be done by scanning one area of the belt at a time and removing duplicate asteroid entries before submitting.
Steps to get an estimate
Buy values in Jita or one of the other Trade Hubs would be the closest estimate to actual returns from an immediate sale of the ore.
There are several methods commonly used in mining, the most basic only requires one account and can be run by very low skilled players, while the most advanced will require multiple players all performing separate tasks in order to be effective.
The most basic way to mine is to fill the ore hold of a ship full of ore and then return to a station to drop it off. Its advantages are that it requires only one character, can be done at very low skill levels and is completely theft-proof. Its disadvantage is that the time you spend travelling to and from a station is wasted (i.e. not spent mining) - however, most mining ships (with the notable exception of the Covetor and the Hulk) have large enough ore holds that they do not need to return frequently to a station to unload.
As an example: An average-skilled miner flying a Venture can mine about 250 m3/min of ore, which is enough to fill the Venture's ore hold (5000 m3) in about 20 minutes. Given that the Venture aligns and warps like a frigate, round trips to a station will take only a minute or two, so very little time is lost. A highly-skilled miner flying a Hulk, on the other hand, can mine about 1600 m3/min of ore, which will fill the Hulk's ore bay (8500 m3) in about 5 minutes, requiring frequent return trips to a station (made longer by the slow align time and warp speed of the Hulk).
(Note: Prior to the Retribution expansion, cargohold mining was very unprofitable, as the cargoholds of non-industrial ships were so small that they filled up too rapidly. However, with the introduction of dedicated ore holds on all mining ships, this is no longer the case.)
Players can jettison items from their cargohold into space, which results in a cargo container (more commonly called a “jetcan” or just a “can”) forming within 2,500m of the ship. This jettisoned container has a volume capacity of 27,500 m3. Miners can take advantage of this capacity by transferring the ore in their cargohold into the jetcan. Typically a player will fill a jetcan with ore, and then (once the jetcan is full) swap to a ship with a larger cargohold (most often an industrial ship) and haul the ore to a nearby station.
If you're flying a mining ship with an ore hold that's considerably smaller than a jetcan (such as a Venture (5000 m3 ore hold) or a Covetor (8000 m3 ore hold)), this method can increase your efficiency, as you can spend more time mining and less time hauling.
However, jetcans only have a lifespan of 2 hours and they are not secure, meaning anyone can open and remove items from a jetcan. This is a common form of theft and griefing in the game, where a player will “flip” a jetcan either to steal the ore or to induce a fight without CONCORD intervention. While it's possible way to combat this by using secure containers (which can be programmed with a password), the largest these (the giant secure container, often called a GSC) can only hold 3,900 m3 of ore, which is less than the ore hold on even the smallest mining ship.
As nearly all mining ships have ore holds which are as large or larger than a jetcan (in addition to the time lost in changing ships and the risk of getting your ore stolen), using jetcans is probably not worth your time. They do, however, come in very handy if you're mining with two accounts or in a fleet (see below). Given their small size, using GSCs for mining is not worth it (although it was a commonly-used practice in the past, when mining ships had much smaller cargo holds).
If you have two Eve accounts, you can multibox them (i.e. play them on one computer simultaneously). One of these can mine while the other ones flies a hauler to drop the mined ore at a nearby station. The miner transfers the mined ore into a jetcan or a GSC (see above) which is then picked up by the hauler. This way, the miner can mine non-stop, obtaining more ore. Eventually, the hauler character could train towards an Orca (to provide mining boosts to the miner, further increasing yield), while the miner character is free to train and fly ships like the Hulk, which have very high mining yield but small ore holds.
Of the professions in Eve, mining and production are most impacted by the player’s efficiency. For miners, it’s all about mining. Time spent hauling, killing rats, moving cans or dealing with ore thieves, can flippers and other flavors of griefers is time not spent making little rocks out of big ‘roids. Anything that can be done to eliminate or minimize the impact of all of those other factors means more little rocks in the hold, which means a fatter wallet.
A properly designed and staffed co-operative Mining Fleets allows miners to spend their time doing what they do best: mining. It also allows the miners to benefit from mining yield bonuses available only to members of a group. These bonuses can add an additional 10% or more to a miner’s yield. If the miners are mining, then someone has to haul the little rocks to the station. If the op is in lower sec regions, something other than drones may be needed to protect the miners from rats, not to mention thieves and assorted other scoundrels. Those protection activities will result in a second “mining” operation as the wrecks are looted and salvaged for the benefit of the op participants.
Our theoretical op has miners, haulers, damage dealers and salvagers; a fairly broad slice of the possible professions in Eve! Mining ops are generally more relaxed than combat fleet ops, co-operative mission running or complex clearing. Chat and/or Mumble deal with a wider variety of topics and separating the required tasks to specialists provides everyone time to participate in the conversations. Not only does this atmosphere provide a social element of connection with the other members, it lets the “teaching” move beyond mining to cover a myriad of subjects.
The next type of fleet is more structured. A standard mining fleet in high security space generally includes a mix of mining barges, exhumers, and haulers (industrials). The miners will work on a single belt constantly, and transfer the ore they mine into a jetcan. The haulers will ferry the resources from space to a station. This makes for increased proficiency as the mining lasers never need to stop, unless you need to switch belts. Fleet boosters are usually present here as well, and an Orca may be used instead of a jetcan. Mining fleets in low-sec will also include combat ships to protect the fleet against rats and hostile players.
Since all the ore is combined into a single pot (and often refined and sold later), you need to agree on a method of splitting the proceeds from the mining fleet between the participants. Since a fleet often includes not only miners with different skill levels flying different ships, but also fleet boosters, haulers, combat ships etc, the simplest way to split the ISK proceeds is to allocate them based on time spent in the fleet; however, this might discourage larger ships from joining the fleet. Scrapyard's Mining Op Worksheet can accomodate several different methods of weighing the contributions of fleet members. Whichever way you choose, make sure that the method of splitting the ISK is agreed upon by the fleet before the mining op starts.