It all depends on how much online time I have to jump over daily news. Keep a close eye on the Movies board, every piece of news posted is an oportunity to make a profit.
Aside from that, play the players, invest in starbonds and funds, and make an informed decision on weekly openers.
I suck at playing long term. I don't hold anything that I don't have a clear view of where it's going.
Finally, clean up your port every once in a while as it grows. You don't want to be stuck with bleeders for too long.
Hope that helps. There are better guides laying around in this forum (Flash usually posts very helpful advice, RazorHawk (HSX Dude) has a very informative website, Kaigee is the source for starbonds, Rocket and his PVL leagues, and of course the insiders who post their stuff in the movies board, to name a few).