What are the best flavorings to use if any to give a little flavor, without ruining the quality of the fondant. Satin ice as well as MMF

I make mmf and flavor it before I add all of the PS. I use either extracts or Lorann's oils.

I also like creme bouquet it gives it a "lemony citrus" flavor.

I've never tried flavoring Satin Ice.

I make only MFF and put 3 oz of white chocolate chips in it when I microwave the gelatin, butter, corn syrup mixture. tastes great.

I make MFF. I substitute various flavored liquid non-dairy creamers for the cream called for in the recipe. I also use whatever extract or oil I want instead of the vanilla. I also add chopped white chocolate as pattycakes does.

I don't really use premade fondants. But I suppose kneading in a little extract or oil just as you would knead in any coloring should work. But I'd be sure to knead it really well. You don't want someone biting into a little pocket of peppermint extract.