Composition?

[Chaser226]

I'm really weak with laying out a good composition. Exciting. Would appreciate some tips on that, and if anybody could give me any advice on how to work on this drawing's background. I want them to be in a forest but it keeps turning out too flat. I mean, I don't want to just draw a bunch of trees across. Totally stuck, i'm here and hoping to learn from some of the best. Thanks in advance.
http://www.timtconcepts.com/images/action.jpg
Btw thats suppose to be a vampire jumping at them.

[ClocktowerArtworks]

thumbnails, thumbnails, thumbnails...make a lot of little sketches until you have a layout that you are happy with. try playing with perspective and cropping. nice start though.

[Danilo]

In my opinion composition is relation between lines, shapes, forms, tones, colours, gradations, contrasts, harmonies...
There is lot litterature about it, I think you should read it. Or do thumbnails and practice your sense for balance.

About this picture I think vampire tooked too small space, and there is large empty space up-right.

I mean, every composition wich follows point of the pic is good.