I hardly had to reach for anything. My "Bucket of Maybes" held a bunch of dried acrylic pieces that I had peeled off the spouts of paint tubes. I had little scraps of hand-painted paper in there, and assorted other bits and pieces.
I am really pleased with how this turned out, and will stop thinking twice about saving little bits and pieces. The element of surprise was the best part of making this collage, and I will definitely give myself the freedom to do more of these. Here's the whole finished collage:
Thanks for having a look.