By buying low and selling high. Buy minerals and mineral-intense ratting modules off the market, refine them, and make them into well-chosen t1 modules. With high enough refining skills, it will be better to buy ore and refine from that. What is a good t1 module? There are basically two kinds:

One: The kind that people will need every day. Other producers will be competing with you for this, assuming you are in a decent location. These will make money based on how well you mind your sell orders, and how long producers have been competing in this location –initially, prices will be very inflated, but competition will (slowly, ever so slowly) drive the prices down.

Two: The second kind of profitable t1 module is the kind that other producers forget about, the high value or rare item that people don't need every day, but when they need it are willing to pay through the nose. These are things like Analyzers, Codebreakers, Large Mobile Warp Disruptor Bubbles, Prototype Cloaks, Interdictor Launchers, etc. Maybe it takes you eighty days to sell ten of them, but since they were for sale at 10,000x their normal price, that's okay. Codebreakers are the best example of this that I can think of. Because they are used by a very small subset of players (explorers) they are often overlooked. They also aren't needed in great quantity, most people probably only use one at a time. So producers don't bother. They probably cost 15k per unit, to make, and I have them for sale for 1m or 600k per unit, in various places.

Ideally you will want an item that has both of these traits:

• Good Profit Margins - The difference between the selling price and the cost to manufacture should be worthwhile. Be sure to compare the absolute profit (ISK) and percent profit (% of selling price) and make sure both are worth your time. What makes it worth your time? It is up to the individual, but strive for at least 10% per item. Profits of 80% have been witnessed by players as young as 2 months to EVE, but they are rare and tend to disappear.
• Good Transaction Volume - If you find an item that is extremely profitable but is only sold once per week, then it has poor transaction volume. There is no guarantee that you can capture all (or even most) of the sales of a particular item! To check the volume of an item, use the Market window. If you choose an item, click on the Price History tab. If it shows a graph, you can see daily sales volume by clicking the Show Table button in the bottom of the window. This will show you how many of an item were sold each day in the region over the last 3 months (default).

• Some people will make three jumps to save a few hundred thousand ISK, some people will not. If there is a better price a few stations away, you will make less money, but not necessarily too much less, especially if it's a PVP module –people tend to buy those in a hurry.
• Some production people will attempt to help the market be less “fuck TEST” and reach a fair price by lowering their prices faster than is absolutely necessary. You will spot these people a mile away. Some people relist in an attempt to control supply and price, but that seldom works with t1 modules unless there is a serious mineral or production slot crunch, or we don't have access to jump bridges. In these cases I will try to drive the prices as close to margins as possible, and when I run out of my supply in that station I will stop producing that module.
• High prices do not automatically fuck TEST. High prices, especially in our front line stations, are good insulation against relisting and, most importantly, combat hoarding. If you put some nice Damage Control Is up for 6k each, in a front-line station that doesn't have any, they're all going to be bought by some TESTie thinking “hey I need Damage Controls and I should stock up for when there aren't any on the market”. Highish prices also happen to keep your pockets lined and your production efforts bankrolled. Any time somebody yells at you for your prices, copy and paste this paragraph. [Needs diplo verification]
• For T1 production, you buy your minerals low, produce the items for less that it's on the market for, and then sell as high as you can. There are additional hurdles you will need to tackle, like where to produce, what to produce, where to get your minerals from, and how to transport your minerals/goods around.

• Build up your blueprint collection by constantly buying and researching blueprints, no matter what else you are doing. This is an investment in an asset, not a sunk cost.
• T1 modules are not especially material-intensive. You can often keep sufficient minerals handy just by having buy orders for them up. Supplement this with buy orders for mineral-heavy modules dropped by the local rats. See here [need to update link] for a list of modules and the minerals that they refine into. I like having buy orders up for armor plates, armor hardeners, and large guns.
• Get a simple production spreadsheet to start with, and use it to manage your orders. As you move into different areas or production you may end up swapping between sheets. After a while you will get a good feeling of what information you use and can customize your sheets to more exactly fit your needs or create something bespoke for yourself.
• Know the area layout. You need to know where the local factories, refineries and labs are, how to navigate between them, where the jump bridges are, how hostile the area is, how good the intel is in our defense channels, etc. Losing a freighter full of minerals probably sucks, so be careful.
• The useful ships for your logistics are: Industrial Ships, Transport Ships, Freighters, Jump Freighters, Rorquals, Carriers. The 'right' ship for the job depends heavily on what you are transporting and where, you will probably start out small with a Transport/Indy but as your operation grows you may want one of the bigger ships - try and factor them into your training plan so when you feel you need them, you aren't stuck waiting for months of training to finish.
• Also, when transporting BPOs, use a fast frigate like a Vigil or an interceptor with enough tank to not die to smartbombs. Best of all, a cloaky nullified T3. You do NOT want to be moving your ME10/TE20 Dominix BPO in an industrial, have it tackled and lose several hundred million in one fell swoop.