What can I do to improve my avatar makeing?

Well, lighting on the tori could be better, to be honest it just looks like you made the background and then threw in the tori. Maybe add some light to the back of him, making it look like he's in the picture. Also try making the scene be about your tori, this kind of draws my attention the the ray of light you have in the upper right corner. The tori is a bit too dark also for my tastes, but that's just what I think.

I think that's pretty much all I have to say for criticism right now, good job otherwise .