After the pots dried (with a little help from my hair dryer--might as well use it for something), I put some play dough into the bottom of each pot and smooshed a cone down into the dough--this was supposed to help the cones stay upright, but it didn't quite work out the way I envisioned. I'm guessing if I had used newer play dough, that hadn't yet had a chance to dry out, this would have worked better. But I didn't want to sacrifice any of our good dough.
Next, the kids glued various shiny things to their trees--we used "jewels," sequins, beads, and some star shaped buttons. I thought about using some thin shiny ribbon for garland, but the kids decided not to. We're currently using Roger's cone tree as our centerpiece.
We also made some trees out of cardboard. I was planning on having the kids use these as Advent calendars, adding one paper ornament each day until Christmas, but that didn't end up happening.
First I had the kids paint a rectangle of cardboard with green paint. They opted to do a wash of gold glitter paint on top of the green. After they dried, I cut the cardboard into tree shapes, and the kids started decorating.
I have a couple more fun tree ideas, but they'll have to wait for another time. Enjoy!