I wont pretend that I've studied photography but I'm obsessed with it, so I'll pretend I do.
The last one is very festive, I like how it doesn't take away from the falling snow. The green on the one above it is vibrant, especially against the brown, makes it really stand out, I really like it.
The one of the flowering tree (Dogwood?), I thought, is pretty but I think with the further flowers in focus, while the up close flowers are blurred makes it hard to look at . What about having them all in focus?
I liked the idea behind the one with the mailbox, the green contrasts nicely with the black and white but the newness of the mailbox contrasts with it in a different way, does that make sense? It seems like you're going for that antique kind of look with the black and white, and if the mailbox looked older, I think it would look better - but remember, I'm pretending that I know what I'm talking about.
I love the one with the eggs, how cute! The first two are really nice as well, what kind of camera are you using? I need to replace the HP one I have, it does its job for the most part, I've just got a lot of gripes about it....