How would i draw the body of a manga/anime?

I've always tried drawing the body of my pics, but i always comes out too big or too small! Or I make the upper body big and as i go down it becomes small and skinny!! >_< ugh! I hav a problem with the clothing too! you know getting all the folds in the wrong places! so please reply me with a tip or post a link to a video or article that gives me tips and maybe some guide lines to help me!! thanks!

Check out Mark Crilley's vids. He has some about the things you are having trouble with. (and some of it comes from practice, but he shows you some tips and how he draws things)
https://www.youtube.com/user/markcrilley?blend=1&ob=4