Well here's some of my advice on drawing:
When drawing, start with a dull pencil and draw lightly incase you make a mistake. It will be easier to erase. Then darken it when you like what you drew.
If you want to draw manga/anime, I suggest watching anime/manga to see how they do it, but everyone has their own style i nanime anyway.
Practice of corse!!!! I'm sure most of the people on this site practiced their drawings to get where they are.
Try using guide-lines when drawing the face or the body so everything's even. But of corse draw the lines lightly with a dull pencil because you need to erase it when you're done.
If you're drawing a body male or female, draw the body before drawing the details in the clothes incase you want to erase something.
Keep your drawings for refrence.
If you draw something you're not satisfied with, don't get frustrated but try to correct it so you can do better ^_^
If you're coloring something, try to do it in one direction so it will look neater.
If you're making your own characters, you can determine the shape of their eyes if you know what their personality and their age will be. Younger characters have larger eyes, older and more mature characters have shorter and/or wider eyes.
Um that''s what I can think of for now. Hope this all helps. Have fun drawing!! ^_^
LadyByakugan96