I've been reading The Power of Habit by Charles Duhigg. He breaks habits down to a cycle of a cue, routine, and Reward and explains that what makes habits really stick is the craving we feel when we get something that we want more of. When I read this I began thinking about how it applied to magic, or didn't apply.
I could see it applying to a daily practice. A person does a given set of exercises and meditation practices each day and receives an award of not only feeling accomplished about it, but also feeling physiological responses that create craving to experience, kind of like a runner's high. I know after I do my meditations each day, I not only feel calm and focused, I also feel a sense of pleasure and that's part of what motivates me to continue doing the meditation.
But this can be extended further. We talk about results quite a bit in magic, and what defines if someone is successful is the achievement of a measurable result. And the achievement of that result brings a sense of happiness, and a sense of power...and perhaps a craving for more results. This could even be where the admonition of lusting for results comes into play.
At the same time creating a habit of your magical practice doesn't have to be about a lust for results, so much as its about achieving a sense of well-being and fulfillment that a person wants to sustain. And then there's the added factor of considering whether the craving a habit can bring about is a conscious experience, or just a physiological inducement that we may not entirely be aware of.
How much of what we do is a result of habit? It's an interesting question to consider both in context to your life and magical practice.