Teagre, welcome to the forum. You will find some good help here and will get all the feedback that you can handle. It may seem a little "to the point" at times, but it is all meant to help you. Folks here do not waste any...shall I say politeness in their comments.
On your first post, one general comment, please number your images as it makes it a lot easier for someone to refer to them - the easier you make it for a reviewer, the more reviews you will probably get.
First impressions:
1. Why are the top two sideways -this makes it very hard to view them properly, so no comment here.
2. The bottom two are not too bad, except your horizons are not horizontal(flat). Both are tilted to the right. The left one is not too bad - the colour in the sky and the clouds is good. The one on the right has very little detail in it and says nothing to me - it is a nice snapshot.