I am completely hopeless with fimo, which is why I used the plastic animals for this project (a little macabre I know). I really wanted it to be gold like a very expensive ring I had seen on boticca which is why I used gold leaf. Its the first time that I have properly used gold leaf so I'm not very experienced with it, there's probably some clever technique you can use which means it doesn't take you a thousand years, get stuck to everything it touches and goes kinda clumpy in some places.
Use your scalpel to cut the head off the plastic horse.
Then cut the horn off another plastic animal. You could also use one of the horse's legs if you don't have other animals, but you'll have to shape it a bit.
Use superglue to stick the horn onto the horse's head and leave to dry. I found this easies to do when I stuck the head down in a lump of blu-tack (or green-tack in my case)
After sticking it down I decided that it wasn't quite the right shape and used my scalpel to trim it a bit. This would have been much easier to do BEFORE glueing it!
Mix some glue with a teeny bit of water in a small pot (mine is a little bit purple because the paintbrush I used had some ink leftover on it)
Paint your unicorn with the glue!
Alternatively you could pant it with acrylics which would be a lot easier and much less fiddly (like yanna k. does in her 'Plastic Animal Makeover' tutorial)
Start sticking on your gold leaf! You can add it little by little and then smooth it down with your paintbrush. You will probably have to add more glue as you go along as I did but I think that's because I used crummy glue because gold leaf fuses to anything it touches (I had gold hands by the end of this project)
Stick your unicorn head to the ring base using superglue. You may want to cover the base in gold before you stick it down because there may be some gaps around the edges depending on how big your ring base is.
Tah-dah! Your very own unicorn ring!