I recommend “Atomic Habits” book for getting a habit.
The book tells us that in order to get a habit, we should start with a small task at first and do this task with 1% more every new day.
For example, at the beginning of the year, you started to make a habit of doing push-ups by doing one push-up in first day. If you do 1% more push-ups every day, at the end of the year you will be able to do 37 push-ups a day.
That’s pretty impressive, right?