if you are a money waster you need to put yourself in a position where you end up the month with more money than you started or at least no debt.
So:
>see how much money you spend each months on fixed expenses (rent, electricity, internet, etc. Groceries are not a fixed expense)
>put aside the money for those bills each month + an extra for emergencies
>spend the rest or save
If you can't do this, you're spending more money than you're earning and you need to downgrade on something (internet, rent… you'll know).
Also don't be a little bitch like my mother, for example, where she considers something like car insurance a "emergency expense" because it comes every 6 months.
When it comes to saving money I learned from the best, since my parents were shitty with money. They managed to waste all the money my dad used to make (he was a top-tier surgeon before going almost blind) and now they live with the poor people State pension. I actually have started to take half of their pension each month to pay their expenses otherwise they would always end up without money. They're not even bad people, or people with sophisticated and expensive taste: they're just incapable of managing money.
Anyway, don't become like them. Get your shit together.