Depending in what timezone you live in you should pick what times you trade, I've noticed that 8-12 in timezone gmt -1 there is very few pirates online, there's not really many players online at all, maybe 40-60 at a time.
You should play when you think there is as few players online as possible, atleast when you trade
Or just go where there aren't pirates... like, say, not Sigma-13 or New Berlin between Planet New Berlin and Brandenburg...
If the OPG are out in force, avoid the Omegas too. That's about it, I just keep tabs on heavy pirate activity and have been pirated all of twice, only once successfully. And that was above Gas Miner Naha in *gasp* Sigma-13.
I typically avoid systems with known pirates in them while trading. Especially because when I trade my profit per run is usually fewer than 500k and many times as little as 50k on a single point to point run rather than in the millions. Its the choice you make flying food products around in a large transport. So getting pirated for a couple mil sets me back quite a few runs. Dont get me wrong, Im still trying to make a little money on each run. The bottom line is not my (the player not the character) motivation though. Character motivation is about getting the goods to the people that need them, making a profit on each run, and not getting killed in the process.
There are times when Ive built up a few million without being pirated and I purposefully pick a route that takes me through likely pirate areas and hope for a good Pirate RP encounter.
So far only one out of four pirates was role played something other than 2 mil or die. That one was great and I wish Id been thinking screen shots at the time, because now I dont remember exactly what was said. (nod to zapp again for his pirate RP on that one)
I know there are additional well played pirates out there. I just dont tend to see them.
Anyway as far as tips for new traders goes; carry goods that fit your RP, form a convoy, get some escorts, and if you have to pay a pirate once in a while, just remember its part of the dangers of your chosen profession.