I thought I would share with you some baby cakes I made for some friends who recently had an ickle one.
I was massively inspired by my new Planet Cake book. It's full of beautiful cake designs and excellent advice to help you make rather exquisite looking cakes. (even if i do say so myself). I would definitely recommend a peruse of that website.
I used the trusty Primrose Bakery vanilla cupcake recipe for the actual cakes. I then used a thin layer of royal icing on top of them to stick the sugar paste to. You could also use buttercream, ganache or boiled apricot jam as your glue.
If you've got a circle cutter that's similar enough in size to the top of your cupcake and a decent smoother, you're well on the way to having a neatly covered cupcake. Simply spread your 'glue' (nice and thinly), place the sugarpaste circle on top and then carefully smooth it down.
If your cupcake has a rounded, or domed top then you will have to do a bit of work on the edges with the smoother, to get them to reach the edges. If your cupcake is completely flat then you will need your circle to be as close to the size of the top of the cake as possible. If your cupcake is uneven on the top, you could use a sharp knife to even it out. Also, vary the thickness of the sugarpaste slightly, depending on whether you need to cover up any bumpy bits!
Once you've got your nice smooth surface, you can decorate away!
Sorry if i got that horrid song stuck in your head...