I vividly remember going through this "collage" phase in the mid nineties. I would just collect anything I could find and add it to my paintings to create masterpieces! Simple things such as kitchen roll, newspaper and string; but also other things such as tinsel, wool, shredded paper, party popper innards, milk lids and bottle tops.
It's weird how some things we remember so vividly. I still enjoy collage though. I worked a lot with mixed media for my A levels, experimenting with creating different textures - I'll try and share some of it with you soon. I think being allowed to experiment early on can really set a person up well to experiment when they're older, and to think outside of the box the world wants you in.
Regulars on my art desk nowadays include filler, silicone sealant, different sponges, sandpaper, chicken wire and remnants of packaging. They can all add different effects and textures to any piece of art, it's all about simply trying things.