Well call me an old cynic, but I reckon reading books on practicing is a very good way of putting off practicing.
It's 3-and-a-half years since I bought my first EC and I've played EVERY day since. Sometimes I'm so tired or depressed or distracted I permit myself to play just one repetition of one tune I know. Sometimes I do stop then, but usually I think, oh that reminds me of this other tune, I'll just play that too....
The best days are when I've heard a tune I really want to learn, then practicing can go on for hours!