Homemade fondant tastes so much better than the commercial stuff and is a lot cheaper than buying it. I have had a lot of success with Michelle Foster's recipe. And yes, she is a real person. Here is the link to her recipe.
A couple of quick notes.
Where the recipe call for cream, I use whatever I have on hand, 1/2 & 1/2, milk, heavy cream, doesn't matter. Also I use white chocolate chips in it as the recipe suggests. Don't leave them out, makes a world of difference.
I buy my glycerin at the health food store, I get a big bottle for about $9.
Humidity in the air makes a difference. On humid days, you will probably use all the powdered sugar in the recipe. On dry days, you definitely won't.
If you need a lot of fondant one color, put the color in with the liquids. If not, when you are kneading it on the table, cut off how ever much you need and color it then. Much easier to do it at this stage then after it has cured overnight.
The handbag pictured above is covered in fondant made with the recipe quoted. It was a dream to work with.