If this is only considered a hobby to you
Bankroll management, If you have to ask then you should probably make up your mind on what you will not feel mad about losing. example in this regard would be, you can spend $5000 on a vacation, you don't feel bad about it because you did pay for what you got.
But to make a long term investment (your time and effort, your cash too to say the least)
I made this my career since 1994 and full time of course, and I am passionate towards it this is my lively hood and how I put a roof over my head and food on the table. I play 500/1000 my bankroll everyday is always the same, my hours are always the same at commerce casino in LA, unfortunately I had to reside to Texas
for personal health reasons.
One word is discipline and your attitude when losing or winning, big or small.