Bob, I'm using PSE, not sure about you. But when you need to make a photo fit in a template space/shape you can use the move tool and make sure you grab a corner so the photo changes while keeping its original shape.
What I mean is if your photo is 4x6 and you need it to be a square for a template, for example, grab a corner of your photo using the Move tool and resize it, and move it around so the part of your photo you want to have showing is in the right place. You can change the opacity of the template shape layer, or of the photo layer so one shows through the other to help with placement. Now, to get rid of the overlap (there will be overlap since in my example we're putting a 4x6 photo into a square spot), put the photo above the template shape in the layers stack. With the photo layer active, choose from the menu, Layer > Create clipping Mask. Or simply use the keyboard shortcut, Ctl+G. This should hide the overlap of your photo. This way you do not have to stretch or compress a photo to make it fit. You don't even need to crop it.
Let us know if you have any questions. We're happy to help!
Courtney