There has been 2 "aha!" moments for me. First would be keeping your emergency fund in a passbook. Yes, oldschool but it will prevent you from spending it unless it's really an emergency. It's such a hassle to go to the bank and have it withdrawn lol.
Second would be renting stuff I only use a few times a month or years. I had not realize that buying things and rare use them are one of the unseen factors of overspending. I rent lawn mowers and canopies on occasion. Some stores can still get pricey with rental fees so if you can rent from a friend, that'd be better. If you don't know anyone, use an app or site for that. Mine is My Garage Rentals!
Easy but effective tricks