If I might suggest a couple of things.

Fine detail in focus is easier to clone than out-of-focus (OOF) areas. This is because the OOF areas tend to have some smooth gradients in the texture. Therefore cloning problems show up readily.

The common problem is to zoom in when cloning OOF areas and on the screen it looks great but when you zoom out to full view, it is easy to see the cloned area as it has disturbances in texture.

I also find that when cloning for sharp detail it is best to not to go over the areas too much as this will make their area less sharp in detail. I tend to use the largest brush possible to clone and then with the mask remove any cloned parts that conflict with the image I want.

There is also a free program that removes wires from jpeg images. It work very well and the only thing to remember when using the program is to stop and maybe change brush sizes every time you cross over unique detail. Like going from sky to brick work.

It works best for power lines etc on sky. Just move brush over object, no need to select source, and remove wire.

As Brian mentioned before it is always best to copy image to new layer first (non-destructive mode)

Wire pilot

http://www.colorpilot.com/load/wire.exe

Niels Henriksen