I don't know that I'd choose to do this on a wall, but cool idea just the same. DIY project using a variety of colorful magazine pages cut into strips. Pick a silhouette/trace an outline. Then cut up the magazine strips and tape/glue it all together.
DIY String Art Projects - Heart String Art - Cool, Fun and Easy Letters, Patterns and Wall Art Tutorials for String Art - How to Make Names, Words, Hearts and State Art for Room Decor and DIY Gifts - (Diy Art For Teens)
In art therapy, the self-portrait experiential is sometimes relevant.a variation here. Collage Self Portrait Instructions: A program for teens, or any age, really. Revised Instructions from Rachel Moani
Quick Teen Art Ideas Its true that art projects take additional planning, but they dont all have to take days or even hours to complete. If youre looking for art projects that your older kids will enjoy, but wont take much time to complete, give one