Hmm... I just kinda doodle on my DS sometimes, and it looks like I haven't been saving some of them. Here are a few I did save...



That female body in the first one doesn't seem to be going too well. The female in the second picture is mostly based on one of the poses I actually did draw in a 60 second drawing. I didn't use reference pictures or whatever... that's just what I learned, I guess. I think I had something somewhat similar to the third picture in a 60 second drawing, too, but it didn't really turn out right. I didn't really choose a specific pose at first, so things turned out poorly.
Here are some of the 60 second drawings I made a couple of days ago or something... Yeah, that third picture is sorta based on one of these.

The ones with exclamation marks are just some crappy things I drew for the hell of it without any reference pictures. I added a few details to the women in the top-right corner and bottom-left corner afterwards... I just wanted to complete them a little.
So far I've only done the 30 second drawings a few times (not necessarily having it set to 30 seconds)... It is quite fun, though, and it really only takes a few minutes. I should really do it on a daily basis. Even those few times have already helped me so much.
As for your advice, Supernatural Cow, I don't entirely follow the hand thing... But copying/drawing things from manga you've recently read does sound like a good idea, and I have been meaning to try it. In a manga series called Bakuman, the main character copied a hundred pages from various battle manga to get the hang of drawing battle scenes... seems like an interesting idea to me, haha. I'm thinking of copying a chapter or two from my favourite series sometime so I can learn more about their styles.