welcome Tassie, magazines are a wonderful source for a personal deck but of course all the images in recent issues are copyrighted so you couldn't make it to market. I've done something similar called Soul Collage which is turning into a pretty interesting Oracle
I've never liked that style of collage for creating. I never seem to find the picture elements I want. I've had more success cutting shapes with yuzen (origami) paper and building a picture from there. Also no copyright problems.