It takes a little discipline but it has worked for me especially in brick and mortar $3-$6 games. Never go all-in pre flop unless you have pocket Aces and are heads up. That $300 bankroll will last a lot longer and it gives you time to wait for high odds in your favor. Just thought I'd throw that out there. Patience is the key.
$300 in what period of time?
100 year life is 24 * 365 * 100 = 876K hours. 30% is sleep time. You will also donate some % to showers, food, and other things like watching BS provided by Hollywood.
Life is too short to wait for pocket aces, unless you're playing 9-12 tables at the same time, like I did. Average salary in my country is $500, I don't think that it's a wise decision to sit on a $300 bankroll for a long time if you're living in the US or
canada or in some other country where you can earn much more money by spending your time with a better use for the society and for yourself than playing poker. I can only recommend you to climb higher, and start calling money at your poker account "a bankroll" when you hit a minimum $2K.
Cause seriously, what is better? To be a King who earns $300 per month by watching cards at the screen or to be a Slave who earns $2K per month by washing floors or drilling holes? By the end of the day, when your fueling your car or buying things at the store or paying your bills - they won't ask you there, if you're a King or a Slave, they just want money.