I've come across this problem a few times and have yet to find a good solution.
If I have two images like below and I want to keep the sky from one and the ground from the other, what's the best way to go about doing that without it looking like total crap? I can't seem to get a good transition at the horizon without it looking terrible.
Sky part I want to use (sky is good, ground is blurry)
Matching ground part (ground is good, sky is blurry)