German without toil

The first thing we want to impress on you is that you ought not to consider the study of this book a drudgery. We firmly believe that you acquire a fluent knowledge of colloquial German provided that you bear in mind two very important things:
First: do not try to do too much at once, but do a little regularly. Half an hour steadily, day by day, is worth infinintely more than a frenzied burst of an hour or two at irregular intervals. Let 'a little and often' be your motto.
Secondly: as far as possible, avoid working when you are mentally tired. When your brain is fatigued, your powers of assimilation become saturated, and the more you try to take in, the less you really absorb.