to get better at your drawing, i would start by tracing over some excellent ones by other people, so you get the hang of it. then try some "look and draw" where you look at the picture and copy it. after all that, make sure to draw lightly with pencil first and don't push to hard when you erase. soon you'll be on your way to making some pretty awesome original manga.

I would say that you should wait a day before you ink over or scan a drawing.
You may find a serious mistake that you would look over right after you put in lots of hard work.

Keep lots of pictures around to use as reference but don't directly copy them.

It sounds cheesy but its true: having fun is the most important thing.
Dont get too serious or you will probably give up.

Check my photos on my profile if you want to see some of my old doodles.

sometimes it helps you get the feel for it if you trace of copy a picture before you start trying drawing free hand, thats what i do if i cant get somthing right. i also practice on my school note books and book covers when im bord in class. hehe

the best way to draw manga is to get a manga with really good art like Vampire Knight and try to copy the way it's drawn. Not the characters the panels. a really good way to get ir right is to use a ruler or straightedge to make all the blocks straight and not crooked. I hope I helped.I tried to explain it the way I draw manga.

I don't know how to draw it personally but looking at manga pictures and trying to copy some of them seems like a good way.
Or try also how to videos on youtube: www.youtube.com/results?search_query=how+to+draw+manga...q=f