Changing habits doesn’t happen overnight. It’s not easy to change habitual behavior and the first couple of weeks—experts say the first 21 days are pivotal—is stressful.

That said, there are things you can do to make your changes stick. First, make the decision to change. Write it down, repeat it in the mirror, post a sticker reminding you of the change you are intent on making on the place where you need the reminder, i.e. the refrigerator door or stick a Post-It in your ash tray.

Second, shape your decision in words that reaffirm your commitment to change. Use the word “will” vs. “try” as in “I will make this change,” not “I’m going to try to change.”

Change requires consistency and persistence. The reward is in knowing you are not controlled by habits, but rather you control your own destiny.