To choose a profitable table it involve skill mixed with observation. I always sit first and watch how others play before joining the table. With that, you'll quickly notice who is bluffing too often or who is playing safe. I avoid tables full of sharks and I go for the ones with casual players...
If you are interested in building your bankroll, patience is the real cheat code. When I started, I was in a rush too much and I lost everything very quickly. Now I just play low stakes, chase small wins, and withdraw often. I even keep a separate account just for gambling so I won't mix with...