violetskies.png
This is so close to taking your graphics up a notch but just has a few things that are holding it back. The main thing is the positioning / sizing of the focal. It is too far to the right and it too big as you have floating head syndrome. Try to keep at least the very top of the shoulder in the canvas so it just feels more balanced and using the rule of thirds, just move it a tad closer to the centre.
Another thing that lets it down are those yellow brushing / dot effects. Firstly, I'd advise against going against such a big contrast in colours unless you are going to have some more hues in between to even it out. Maybe if there was some reddish hues worked into the background it could work, and you'd have to bring the opacity up a bit cause they are just getting lost and look a bit messy.
I don't mind too much the white outline around the render because it gives it a distinctive like manga / cartoon look which is not bad. However the borders aren't adding anything in my opinion. As a general rule, most of time it is safer to go without a border, unless you have solid black / white (not 1px) to add some atmosphere and break it up from the page around it.
To end on a positive note, the text is amazing. Not just a great font choice, but it is positioned wonderfully, and that squiggly line sits very nicely without detracting from anything or throwing off balance or whatever. Very nice indeed!
Hope that was alright! Not intended to be harsh or mean, just trying to point out things that can be fixed so you learn more rather than just praising things. So yeah. :D