First of all why would you want to create a habit?
Well, for me, it makes something unpleasant a bit more pleasant.
I wanted to exercise, but I never got to it for a long time, I would usually stop after 2 days and never return back until I decided to do it again. I discovered that I need to motivate myself enough to endure the first month of the periodical activity and then I feel bad for missing out. I now exercise every other day and if I miss I better have a really good excuse to justify myself. The trick really is just to endure the first month with every bit of motivation and discipline you have and then it will become easier and easier.
Good luck!