What are the best ways to change bad behavior and habits?

Have you changed things about yourself that you know have held you back? How did you succeed? The only person you can change is yourself......so I want to do that. What is the best way to go about it?What are the best ways to change bad behavior and habits?
I had this obsessive thing after my dad died, Where I needed to hear from my boyfriend/friends/ relatives when almost all the time. What I did was set times I could text or call them so that way I wasn't always annoying them, and I would only set 2 at first and then lowered to one time a day, and now I can pretty much at normal and don't need to hear from them all the time. I do have my moments sometimes thoughWhat are the best ways to change bad behavior and habits?
Shock Therapy. If you do a bad habit in front of someone, have them zap you with a taser.