suggestion: choose a few lessons to practice
Practice all skills practices the skills I haven't practiced in the longest time, but they are now easy. What I would like is to choose let's say 2-5 lessons to practice from, or to choose all "adverbs" or "verbs" and so on.
I go to the particular skill that I want to practice, click on it to show all of the lessons in that particular skill, and then click on the lesson where I think I need work in order to repeat it. A repeated lesson will be similar but not necessarily the same as when you saw it the first time, so the danger of memorizing phrases isn't too great. That said, I'm not that far into my skill tree, so this may not work as well for someone who is more advanced and has a lot more skills (and lessons) from which to choose.