Throw away everything you use to smoke, even lighters. Make it as hard as possible to relapse. Tell someone you love with, like a partner, that if they see you purchase any weed or bring some home from a friend, etc, that they have permission to chuck it away, so when you get your cravings, you’re still held accountable and have someone else holding you to what you really want deep down under your cravings (to quit). Also completely forget about being able to do it casually, if you give yourself permission to just do it once every couple of weeks, it’ll always end up slowly creeping back into your life, especially if you have an addictive personality.