beginner: critiques for short gesture drawings

Hello. I am 15 years old, and for a while now, I've begun to take art a lot more seriously and would like to improve. Here are links to some recent gesture drawings I have done using the models from this website.
http://fav.me/d8zdji9
http://fav.me/d8zdkby
I would like to know anything I need to improve doing these, or if I'm even doing them right at all. Thank you!

Wow, they look great! I'd only suggest you to ground your figures and cross their faces to indicate where they are looking. You might also want to add hair and include the line of action in your drawings. Other than that, keep practising ;)