A fun way to decorate a cake is to sew some punched shapes with thread to make a banner and string it up between two wooden skewers.
This is a Birthday Bundt cake I made for a dear friend. Lots of different punched shapes would work well for this. Try the Simplicity Geared classic range
and see where the inspiration takes you. (Looking at this picture anyone would think I liked chickens!)
If you want some inspiration on seasonal decorations you can make using your Tonic punches, then check out the Papercraft Post
. Susan Niner Janes has a great tutorial on paper chains and more.