It helps if I can see a benefit to continuing the habit. I developed the habit of going to the gym a few years ago, and managed to stick to it for several years because I could really feel the benefit. Sadly through lack of time I've stopped going recently but I definitely intend to start again!
I've recently resolved to eat more healthily which will involve a lot of determination and concentration! I've made a good start by being organised and making lots of lists so I have time to shop for the right ingredients and cook well-balanced meals. Let’s see how that goes!