So I don't like normal fondant because its just not very yummy so when I decorate cakes I tend to only use icing and pipe things which anyone will tell you isn't always the cleanest. You can work really hard for clean lines that don't always happen. So your next option is fondant which is pretty easy to work with and makes a very smooth surface on cakes but as I said before its not very tasty. So after some googling and a helpful nudge from a friend who tried it I decided to play with marshmallow fondant! It was super easy albiet messy!
Grab a bag of marshmallows, crisco, powdered sugar, and a little water.
Put the bag of marshmallows and 3tbl of water in a glass bowl and microwave for 30 seconds, stir. Do this at 30sec intervals until the marshmallows are melted. It should take about 3 minutes total. Let this cool for a few minutes because if you start mixing it while its still hot you will have a huge mess and its harder to mix. Now take your crisco and grease your surface VERY WELL!!! Also COVER your hands in crisco after you do this next step.
Add 3/4ths of the bag of powdered sugar(2lb bag)to the top of the marshmallows and mix with your greased hands. Once you have it mixed together pour out onto your surface and continue to knead like bread dough. If it seems to dry add water and if it seems too wet then add more powdered sugar. I had to regrease my hands several times as well as my surface just FYI.
Knead until you have a smooth ball of marshmallow ball and cover with crisco then place in a ziplock bag. Before you close the bag try and get all of the air out. This should stay good for a week or two.
You can do the same thing with a can of white icing and powdered sugar without adding the water.