What is everyone’s opinion on this subject? How do you know how much to keep in, when do you know its a good time to cash out?

Personally I never like to try and build up a enormous bank roll because I know i’ll just always end up playing higher limits and never cash any of it out. So I like to cash out every time I get up 100-150 dollars. I always like to keep 50-100 dollars to play around with.