With a white cloud-cover like that and some intermittent sun, it might lend some depth to your pictures if you can use a polarizing filter. This can also help you towards not having parts of them overexposed (just a few spots on the last image).
I actually did bracket the exposure on a few of them with the intention of rescuing the highlights but in the end I didn't use it. I didn't post-process these apart from cropping a few of them. I'd like to say that this was a matter of principle but it was, in fact, just laziness
I'll probably boost the saturation a bit and save the highlights when I put these on my website.
Also, I like 5 and 6 the most too!
Thanks for taking the time to reply.