For the Snowmen, we used cotton balls, twigs, sequins, ribbon, pipe cleaner and other odds and ends. There is no limit to what you can use. White glue or hot glue is needed though so really delicate items or heavy things might not work. I had thought to use buttons, but I could not find my buttons.
For the Christmas trees, I had used fern for the older kids, but probbaly should have dried or pressed the fern first since the fresh fern was either too springy or curled as it dries. For the younger kids I ended up cutting some very nice flat cedar branches. Eiher way, these cards will not last forever, but they are cute.
The younger kids seemed to be more free with the project then the oler kids who had higher expectations. But all the results are super cute!!