I use a Money Management system that is divided on two different levels: Regular Play (4 units) and Top Play (5 units).
My recommendation is to establish a bankroll of 300 units (you select how much $$$ an unit is worth) and then, you should bet the following on each play:
Regular PLAY = 1.00% of the bankroll
Top PLAY = 1.50% to 1.67% of the bankroll
E.g. Someone with a bank where 1 unit = $100 (bankroll: 300 units x $100 = $30000), should bet $400 (4 units) on a Regular Play and $500 (5 units) on a Top Play.