C&C per req:
A nice enough set overall, but I'm NOT a fan of the dull, white, featureless sky in the first two. I would suggest either exposing to allow some detail, or compositing another sky in. The framing in #3, is very well done, 'though a bit could be cropped off of the LH edge with no harm to the image IMO. #s 4 & 5 both need fill light, and I find that in #5, they're just too little small in the frame.
Just my $00.02 worth - your mileage may vary.
~John