You can blend two or more photos to get a unique picture. I used a picture of my dog cracker and a hunting scene photo.
Open an existing image. I am going to use the image of the man and dog on
the lake excluding the puppies head shown above. I will refer to this as the
background of the picture.
Add a new layer by clicking on Layers>New Raster Layer>OK or clicking the new layers icon shown below:
Open another image. I used a picture of my dog Cracker.
Pick the Point to Point option under the selection dropdown list. Draw a selection around the picture you want by left clicking around the picture and double clicking to make selection. I selected just the head of Cracker.
Point to Point Settings:
Feather = 0
Anti-Alias = Checked
Click on Selections>Modify>Feather (Pixels = 15)
Place a copy of the current selection into your clipboard by pressing [CTRL+C]
Click on the background image and press [CTRL+E] to paste the selection onto the background.
Right click to place the photo in the picture where you want it to appear.
Press [CTRL+D] to deselect the selection.
Click on Layers>Properties, set Blend Mode = Hardlight
Experiment with the Blend Mode and Opacity settings. The settings I used are shown below: