I think bank roll management is the only factor that can be attached to winning strategy that he is pertaining because you can increase your percentage of winning if you only bet a proper amount in proportion to your bankroll to last longer in the game and hit the bonus round as early as possible.
I don’t play slots most of the time but I usually stop playing whenever I hit bonus round using free spin to secure my profit. I think this can be considered as winning strategy.
I agree. Bankroll management is a very important part of being a great gambler, any veteran gambler would know that you do not go all in right away and make mistakes, you need to make sure that you are doing something decent with the amounts and could go on for a while before you run out of money. That's not a common thing done by people all that much, but I agree that it is going to be something special when you do and you could earn more money that way.
This could be done by studying and learning how to do bankroll management. If you like reading there are articles, or if you like watching then there are youtube videos about it that will teach you how to be a better gambler.