Every payday you pay yourself cash...leaving a the amount in your account for monthly bills, gas etc.
Because cash is so inconvenient to use, it's easier to save, and that takes training. Want a new TV? That cash stash is over here and when you have enough you will look at it and ask yourself....do I reeeealy want it?
It took me 3 months saving tips and also selling my Xbox at the end of that time to splurge on a steam deck. Worth it.
My wife used to budget cash for me out of my check, and that suited me judt fine (she handled the household budgeting) and I was able to buy gifts without anything showing up on our account, get myself things without trying to figure out if I was over spending, and save up for mods for my then hobby driving offroad and camping.