First, fold a few coffee filters in half and cut the center circle out.
Open a filter and place it over the top of the foam cone, like a ring, and bring it all the way down to the base of the cone. Use the stick pins to tack the filter to the cone, pushing the pins in at the top of the filter, not down by the ruffles.
Repeat this step, working your way up the cone.
When you get about half way up the cone you will need to trim a little off the filter ring. Since the cone will naturally get smaller toward the top, you will need less and less filter as you work upward. Just trim off what you don't need, but set those pieces aside and use them at the top of the tree.
Use one of the center circles that you cut out of the filters to cover the top of the cone, securing with stick pins.
To decorate the tree, push round topped pins into the tree in various places, but don't push the pin all the way in. This will allow the ruffles to look more natural. If you push the pin in all the way it will flatten the ruffles against the cone. So push the pin in halfway or three quarters of the way, then gently pull the filter toward you to hide the pin section.
Use hot glue to add buttons. I glued the two flowers together, back to back, so that either side of the tree had a flower face. Glue that to the top of the tree. Then just glue it to your base (I used a round slice of wood).