Well...
Your first one isn't all that bad but, it has a lot of empty space - Best to try and fill it up with other things than just brush strokes. For your second one, I would try and dull it down on the background colors because they seem to completely take control over your image and over-power everything else.
Over all. not so bad. Keep up the work but, be sure to try your luck at using some Tuts as well.