The habit that you have to avoid when gambling is:
Don't make a lot of bet while gambling
This is the reason why people lose. When you make a lot of bets, you decrease your probability of winning in total profits.
Making lots of bets not increasing your chances to win but the other way around, it can decrease your profitable earnings since the numbers of winning can be much lesser than the number of your winning chance, enjoying instead of focusing and aggressively try to win over and over.