My favorites are #2 and #4 just because of their composition. The angle in #1 really was dull for me and #3 just didn't spur my attention and hold it. Overall great photos though...keep shooting.
You're asking about things that might be done in pp?
Well, if it were mine, I'd clone out those two stray twigs in 3 which reach into your frame from above. You know which two I'm talking about?
And in Photo 2 I'd clone out that next tree which shows only just so little on the right.
I actually looked at Photo 1 for longer, taking in the straight verticals, which are really straight, which I like: the post, the main tree, the background trees. And suddenly, towards the top, that main tree breaks out of its straightness and divides ... I like that.
And I like the last, though it would have been nice to be able to follow that creek further into the pic and not have it end in a "cul-de-sac". Though I believe something very man-made would have shown in your frame had you stepped further to the left?
All in all I get the feeling that at this time of the year, the countryside "at home" is as bleak and dead (and waiting for spring to come) as it is around here...