I made a fun fern out of soda cans and I think it's pretty smashing!
So I started off by cutting pieces of corrugated plastic (from my stack of recycled election and campaign signs!). I painted the pieces brown with the Krylon paint that bonds to plastic. I then glued the pieces around a planter salvaged from our community dumpster. This can be tricky, and I recommend using clothes pins or other clamps to hold the pieces in place at the top as they can be quite springy!
I then filled the planter with spray foam insulation, available at any hardware store. Tip: when the can says only fill 50% of the space you want filled, THEY MEAN IT! Be sparing, and be sure to allow it to harden overnight.
After my pot had 2 layers of "wood", and my insulation had dried, I sanded and glued floral picks onto pieces of soda cans I had cut to look like ferns. I then arranged them (carefully) in my hanging pot and I am tickled with the result!