If the habits that you are trying to inculcate in you are dear to you, you won't need much motivation or willpower.

We normally think we need more motivation and willpower to succeed. But motivation is inconsistent and fickle, and you cannot rely on it daily. You would need to hack your environment, and design the surroundings around you to facilitate progress towards the goals.

Less than perfect is still beneficial. Something is better than nothing.

Focusing on what we have, what the positive side is, and what opportunity arises out of the current situation, is the answer to sticking with our goals.

Even doing something small towards your goal can help build a daily routine.

Schedule your habits by giving them a specific space in your daily waking hours. You can put it in your calendar, or link it to your current behavior patterns. 

Most of us fail in our endeavors at some point in our lives, whether it's a New Year's resolution or a health goal you are working on. These setbacks make us human, not a failure.