Blending Three Photos - some tutorials

You might find these useful for the next club competition set subject "Image Combination".
The challenge requires your final image to be made up of three separate images. These images can be overlapping, "cutout" (extracted) or merged (blended).

Here are the three main techniques you might use and some tutorials you might find useful:

Erase (PSE, Photoshop CS)

Erase everything you don’t want - BUT erasing is permanent so you can’t easily undo your changes without starting again from scratch
Face on a Pear
How to Combine Photos Using Photoshop Elements 10 (or earlier versions - uses magnetic lasso)

Clipping Mask (PSE, Photoshop CS)

The mask is a separate layer that you “clip” your image to. In this method
transparent = conceal
everything else = reveal
You can clip multiple layers to the one clipping mask.
Blend Photos Like A Hollywood Movie Poster simple tutorial

Layer Mask (PSE 9+, Photoshop CS)

This method gives you the most power because mask is added directly to the same layer as the photo.
On the layer mask you use a gradient or paint brush to paint in the areas you do want using white, paint out the areas you don’t want using black (NOT by erasing)

 “black conceals and white reveals”. 

Photoshop Elements: Creating composite images | lynda.com tutorial youtube
Adding Reflections to Sunglasses - Photoshop Tutorial
Bride and Groom on a Wineglass