What matters is being able to do. To do you must copy analyse and apply. This is what John K's Lesson 9 is all about.
It doesn't literally mean just copy all these model sheets (although that's a great idea)and then your done. What it's really saying is keep copying analysing and applying from great drawings (and sometimes life) all the time, as a training. The more you do, and the longer you have been doing them for, the better off you'll be.
Most people (including myself) forget about the apply part. This is really stupid. You will not much apart from how to copy unless you keep practicing how to apply. I think the best ratio is about 50:50, or one applied drawing for every analysed/copied drawing (maybe a bit more copying at the beginning is ok). It doesn't matter if the applied drawings really suck to begin with, this is part of the process.
Here are some of the applying exercises I do:
1) Change the pose/angle of the character.
2) design a new character (using similar features?)
3) Adopt the same pose with another existing character
4) Draw from memory
There are probably many other variations on this also (maybe some involving a storyline). Experiment!
Anyway, below (and in the post before) are some pages from my sketchbooks that I havent posted yet. Some are applied pictures and many suck. That's ok because it's part of the process.
Soon I will be working through the composition lessons (with the same process) :)
Yes, I will do more overlay checks. It's quite time consuming though (scanning software analysing reworking etc). Great for checking blind spots.