Gambling is not a one shot trade. You are suppose to gamble day after day after day. So I think the main rule is to protect your capital. If you have $100 in your pocket, bet $1. If you have 1000 at your disposal, bet 10 on each game. Make sure you don’t go broke. And if you wanna learn from your past mistakes, write down everything you can. At least every single bet you take into a spreadsheet of some sort. This is the only way to have an impartial history of your performance.