I just came across this great video and app which you can use to scan in your old photos which you may want to use for you photo collage. The app is called Shoebox. https://www.youtube.com/watch?v=2Ys8eaFZB_A
You don't need to use this app by any means but its very neat.
Here's how to do it without an app,
Place your photo on a flat surface in a well lit room . Making sure it snot reflecting any direct spot lights.
Take your phone and make sure the camera is set to the highest possible quality / resolution.
Turn flash off
Take a photo and make sure you are at least 4 - 10 inches away so that it can focus, each phone will vary but you can tell by watching the screen.
Take at least two photos of each picture.
When you send me these photos I will crop out the photo so all background is gone. I can also correct angle/perspective if needed and correct the colour and lighting.