Definately progress over your first two images, nice job!
3- I'm not keen on the lines you are trying to create in the first image. They are off center, which works, but I dont like how the focus is right off the accumulation of snow. It makes somethine interesting to look at, but my eye stays stuck right on that snow accumulation line
4- Ok...NOW we are talking photography here. This is definately showing someone who is trying to MAKE an image instead of just CAPTURE an image. I really like the choice of DOF here, keeping the background nice and blurry. Its a wee bit too shallow for my taste (might be artistic differences) as I would like the whole piece of ice in focus.
Nicely composed as well, having the image off center and a bit to one side. The blue in the background adds a nice sense of cold to the image.
Still not matching your thread title, but nice job going back out and doing more. Read into using leading lines in images to help with the #3 image.