Powerful indeed is the empire of habit.

Most of what you do in a day was not decided today. Habit runs quietly underneath intention, and it will outlast almost any resolution made against it, because the resolution requires attention and the habit does not. This is why willpower feels strong for about nine days and then stops being available.

Rather than resolving harder, change the conditions the habit depends on: what is within reach, what happens immediately before it, who you are with. Make the thing you want slightly easier and the thing you do not want slightly harder. Small changes to the setup beat large changes to your intentions.