Developing a new habit is more about creating the habit itself than the actual behavior. Exercising is far easier than creating a daily habit to exercise.
Knowing this, the hack is to create a routine that takes 30 seconds to accomplish and repeat it for 21 days in a row. Floss one tooth. Do only three pushups. Sit and take just three breaths without trying to meditate for 30 minutes. Resist the temptation to do more.
After 21 days, you’ll have done the hard part (creating the habit), and you can add as much time or as many reps as you want.