There is no substitute for Charles Duhigg's book for learning about habits and how to rewire them or Roy Baumeister's book for how to improve your willpower. But if you don’t have time for a whole book, this post by Sharbani Roy on Nir Eyal’s blog has a great, practical summary that is based on solid behavioral science. Plus, she has lots of links to related material so you can keep going if you want. This is not the shallow pop psychology you see on Oprah and Dr. Phil (sorry, faithful readers, but that stuff is pretty hokey). This is the real deal.