Actually, I have little problem finding trade routes, except for the occassional brain fart.
The secret is not 3rd party software, and it is definitely not using the 'import/export' listings in the market - they are the low-margin routes because everyone does them (including the NPCs, if they count).
Let's say you are at an extraction planet: Regardless of what it imports, it will need: Mineral Extractors, food, power plants, explosives. (Good place to pick up ores.).
An industrial planet will need metals, certain components, foods, and is a good place to pick up lowtech finished things. A refinery planet will need ores (And a good place to pick up metals).
A hitech planet will need metals, components, luxuries, foods. An agricultural planet needs agrimeds, domes, all sorts of stuff, good source of foods.
It's mostly logical from the descriptions. Use your head/intuition and you'll make a decent profit.
Avoid service/tourism planets. They may offer good prices on some, even most, things, but you can't pick up anything.
PS: You won't make millions per route. The best you can expect from a run is 500 per unit, but usually less. Sometimes a golden route with more, coinciding with a decent trade mission.
PS: Trade missions that say there's a shortage of something somewhere aren't necessarily right. Don't use them as trading advice.
PS: More expensive things give higher payoff per item in value, but less in %, usually. You can easily put your entire fortune in your cargo that way. It's a bit risky, because while your ship is insured, your cargo isn't. Usually it goes well, but as a trader you'll run that risk every time. Don't put everything you have in a gamble, like I do.
PS: A tip from the novel in the original Elite: An empty hold is an empty head.
Lastly, what about the ship?
I liked the Hauler - not because of its huge cargo hold (it wasn't) but because its field shift drive was easily upgraded to give you 25+LY range and really low fuel consumption - you could easily go halfway across the galaxy on one tank on it. (But that's not really what you do for trading). Anyway: I ripped out weapons, shields, discovery scanner and put in the lightest versions of everything else, all for range, fuel economy, and max cargo hold. I won't recommend that for more expensive ships, but it worked nicely.
