This is a tutorial on how to blend two images together into one single image. What you do first is open up two images that will blend easily together. It's best if their standing in the picture.
I'm going to use these two,
CLICK IMAGE 1
CLICK IMAGE 2
Next you click on one of the pictures. Go to select>then all. After it's selected go to edit and copy it. Make a new document by going to file > new. Make the document large enough to paste both images in it. Then go to edit>and paste.
After the first image is pasted onto the document, go back to your second image and follow the same steps. Go to select>then all. After it's selected go to edit and copy it. Make a new document by going to file > new. Make the document large enough to paste both images in it. Then go to edit>and paste.
If your document is large, and it has extra background in it, just crop it.
Moreover, Overlay the two images together. So one of them is on top of the other.
Next you grab your eraser tool. 
and erase around one of the pictures.
After you have done that. select the picture you erased the background of, go to select>all. edit>copy. Go to image>image rotation>Flip canvas horizontal. Now you have another copy of one of the pictures.
after your satisfied and pleased with the outcome right click layer one and click merge visible.
It should look like this..
