Whenever I create a new set of habits, I get overwhelmed with a sense of motivation and optimism.
Unfortunately, this feeling is largely bullshit, and ultimately unhelpful.
It feels helpful at first - who doesn't like feeling motivated and optimistic? But the problem occurs after a few days, when life kicks in and things get in the way.
Maybe you miss a couple habits. You fall off the wagon a little. All of a sudden you feel less optimistic, and therefore less motivated. It feels hard. It feels like things will never get better.
See, the trick to good lifestyle design is to pick a habit stack that you can largely sustain even when you feel UNMOTIVATED and PESSIMISTIC.
Those moments when you feel on top of the world are the exception, not the rule. Habits that can only be sustained during periods of emotional exuberance are habits that will not be maintained.
Think about the days when you feel like absolute garbage - what positive habits do you think you could maintain even on those days? Start there.