Aligning and merging hand hand shots can be difficult.
I managed to get the following shot of a cockatoo launching across the moon. At the time I was focused on the bird, so the moon was out of focus and the apparent surface area enlarged. I immediately took a second shot, focused on the moon. The shots were hand held - so there is a little camera shake in both. I was not too worried about the bird - the low light and movement meant that some blurring was going to be inevitable.
To merge the two in-focus areas - the bird from the first shot and the moon from the second - I first removed camera shake using smart sharpen and then aligned and cropped the shot. I then merged giving me a sharp moon, but with the white balance flooding out the details you can see in the in-focus moon. I applied a filter to the merged composition and restored the surface detail of the moon using an exposure and contrast layer.