Get rid of credit cards, or call and ask for a very low credit limit (i.e. $1000) so you have something in case of emergencies. Remove your credit card information from sites like Amazon so if you want to buy something you have to go through the hassle of re-entering it all again. Sometimes you don't have your card on hand and this can be good. Start using cash. Instead of using the debit card, carry around cash and spend down from that. Have a real conversation about your money goals, short term and long term. What's something you want in the future that money can help you get? Getting in the habit of setting aside money can be hard but also very useful. Get separate bank accounts at different banks. Or keep most of your money in savings so your checking account is smaller. Avoid online shopping at work or when you're bored. Consider taking a shopping buddy with you when you go to the store. Put an item on Amazon into your basket and keep it there for 1-2 weeks before actually buying it. Sometimes the impulsivity to buy it will have gone away and you won't feel you need it anymore.

Those are all things that have worked for me.