if we ignore the fact that Akira Toriyama, while its unique, has a very ugly way of drawing anime, there's still lots of things to be adressed... lets start from the top...
I'm using a tablet and photoshop which i am not at all acustomed to... so my skills are impaired, bare with me.
http://img509.imageshack.us/img509/873/tut1il2.jpg[/img]
See the red stuff i faded out under that? That's called Under Structure. Do not be afraid to use it when drawing, 90% of all professional character artists do, and 100% of all cell animators do. It allows you to get a feeling for the parts of the body as a basic before you go doing details.
Now a few basic Structural things...
Only draw what you can see, if you can't see it, don't draw it. When you turn your head to the side, the ear facing away from the viewer is hidden. Don't draw it. Even if you feel you must draw it, you've got 1 ear that's almost in the right spot and another ear protruding from his neck. Top of the ear should be about eye level, bottom should be about nose level.
He has a pez neck. Meaning his neck just juts straight up into his head. The neck curves. Draw it as such,although i didn't do a good job illustrating that in my example =\
His shoulders don't align right. At the angle he's drawn, his neck and collar bone face one way and his shoulder mysteriously pops out and comes down to a full-front facing position. Keep your body parts aligned.
http://img444.imageshack.us/img444/2649/tut2fj1.jpg[/img]
Ok building on what I said for the last one because i'm not repeating myself for the same mistakes..
No matter how cool you may think neck muscles are, a.) a guy with his build wouldn't have big ones and more importantly b.) they would never ever ever look like that. They would be much more sloping gradual and they would NNEEEVER make such a sharp angle when connecting with the rest of the shelf of the collar bone. If you insist on having long necks, don't do the DBZ bulging neck/shoulder muscles.
See the pony tail? no you don't because it's hidden by his neck. Dont' draw it. I know i said I wouldn't' repeat myself but, Don't draw it.
I failed to mention this before, but ears do not connect to the jaw line.
The body has Mass. Things have to fold around the body. This includes your arms. Your arms are connected to your shoulders. Once again your shoulders cannot magically twist around. So if you fold your arms, you have to wrap an arm around the body.
I didn't get into the hands right now because they more delicate and require a full explanation all their own. One i can't give w/ just my tablet, and I'm not at all in the mood to scan anything right now.
I hope this helps. Sorry if this is a little bit Necro-Posty, but as i was sweeping through posts... i just had to.
Edit: oh my loving mother there's more on page 2 and page 3 for me to mess with ><
I'll do that tomorrow I'm not up for anymore right now ~.~
Edit again: If you take your art even remotely seriously, NEVER draw on lined paper. it's a sin o.o get a decent sketch book or at least use printer paper. Nothing screams "i don't give a sh*t" like a note book drawing. Especially if you're using it for somethings serious o____o