I am trying to keep a notebook of notes/figures/even sketches that I can use to practice, review, etc. Does anyone else do this? What kind of system do youuse?

Bee. I was always told that I must learn the names of the different moves that I make. Otherwise it is like putting a document into a filing cabinet with no file name on it. I do know a guy who was never encouraged to do the above, and for several years danced that way. Believe it or not he can't start on anything that could be 3/4 of the way through his routine without going all the way to the beginning. In other words if asked to start at the Open Impetus he is completely lost. So it is a good idea to own a technique book and make sure that you at least know the names, and are able to do all of the basic steps.

what's a good technique book? do you have any recommendations?

Hi bee
A good technique book is fine, but i assume you're talking about taking notes at a class, where the coach is pointing out your weaknesses and correting them...etc. The technique book doesn't cover everything.
I use beats in the bar. If there's a head movement, or a particular thing i should be aware of on a particular beat, i note it down. Also if the grouping of steps has a name, i write that down too.
Before anybody writes comments about "we don't dance on the beat" and "this will make your dancing mechanical" just let me quickly point out that this is while i'm LEARNING. Once i have the hang of it, i use it as part of my dancing without worrying too much about beats.
The most important thing is that it's impossible to remember everything in an hour or two hour lesson, and so make a note of it in any way that's comfortable for you
If you find a technique book that's up to date with the modern approach to competitive ballroom dancing, please let us know