While I have used “no name brands” in a pinch, I find that using the better quality ingredients do make a better quality fondant.
Ingredients needed are
1lb powdered sugar
1/2 cup Crisco (original)
16oz bag marshmallows (MMs)
2-4 T water
I microwave the MMs 30 seconds at a time, stirring each time until they are melting together, usually a total of 1 1/2- 2 minutes. I grease a large bowl with a thin layer of Crisco (to prevent the MMs from sticking to it) and dump in half the powdered sugar. I add the melted MMs and the 1/2 cup Crisco and stir like crazy trying to incorporate it all together. I use a big spoon but you can you your hands, grease them first though!
As I mix I add the rest of the powdered sugar and then the water just a little at a time to make sure I don’t add more liquid than I need. I usually use all 4 Tbl but we live in a dry area. Continue to mix until you have a nice smooth texture! Place it in a airtight Ziplock. In between using it I smooth on a small bit of Crisco to act as a layer against drying out. It is very useful with store bought fondants like Wiltons that have become a little too dry, I just mix in a little MM fondant and it moistens it up enough to make it flexible again!