Building/breaking habits became far easier to me when I started to understand the true importance and power of choice in the present moment. If you can cultivate the ability to fight with yourself in the moment - when you do (or don't) want to execute - a habit is really just reduced to a single choice during the day. I still have to do it every night when I'm tired and don't feel like brushing my teeth... but I've had no problem running/lifting regularly since I was 18.

If you think about it, character is really just the additive (or multiplicative?) result of thousands of tiny choices we've made along the way in each present moment, for better or for worse. The only time you can be the person you want to be is right now -- including building or breaking habits. A choice promised to the future has no power or worth, the only time it matters is in the present, when it's time to put words and dreams into action.

In the case of habits, the long-term will take care of itself by focusing on the short term. Win the small daily battles and you'll be on your way to winning the war. And don't forget to manage expectations and give yourself grace when you lose a few of those battles. Something is always better than nothing.