Replacing a Sky Background
Have you had a great photo but the sky was washed out making the photo dull and uninteresting? Well not a problem with Adobe Photoshop. First you will neeed the sky photo. I used the one below. Save it and open it in Photoshop.:

Then open the photo you want to replace the background on. I used the photo below:

We will start with the castle photo. The first thing you need to do is make the Background layer act like a regular layer. Double click the Background layer in the layer palette to bring up the New Layer dialog box. Type Castle in the Name text box and click the OK button.

Select the magic wand tool
with tolerance set to 50
. Click on the dull sky behine the castle to select it. You should have marching ants around the area you want to get rid of:

Press the delete button to get rid of the background. Click Ctrl + D to deselect the area.
Now activate your sky picture. Click on the rectangular marquee tool
and select the part of the sky you want to use as your new background:

Click Edit > Copy, then click back on the castel photo to select it then select Edit > Paste. Click on the Move Tool
and drag the sky up to the top of the document. Next you need to resize the sky so that is covers the area where the original sky was located. Click Edit then select Free Transform:

Grab the handle highlighted with red below and drag down your sky so that it fills up the background. Click the check box
at the top of the document window to accept the resize.

The last thing you will need to do is drag the sky background under the castle background in the layers palette:

Here is my finished product:

What a difference!!!