ditto the above. Best way to build a bankroll is not spend or decrease ur bank roll...i.e. find a sustainable way to make it go up and continue whatever activity that is.

try sngs, cash, mtts. find your niche. If you have 0 dollars, then play freerolls until you have a few buy ins.

if you are bad at poker than stick to freerolls and spend 90% of your time learning from videos, forums, and ur freeroll mistakes or successes.

realistically, the best thing to do is what you find to work. this means that you will invariably be risking ur bankrool to find out. just win a lot of freerolls and bring up ur bankroll, to where you have enough buyins to where it wont hurt too bad.

if ur decent i find 2nl on bcp to be the weakest cash game u could play.