Glad that you have your own theming thread to showcase your work now, SK.

I like your quotation theme the most. Clean, nice icon set, readable texts.

The alien theme looks ok, but the softkey & status bar are a little too busy IMO. One handy tip, when you make your big preview, when your theme is already busy, you might want to use just plain background. The alien theme looks even busier with the carbon/mesh background.

Looking forward seeing more of your work.