So, for each can of refried beans (you can even use fat-free), stir in 1/3 cup of SOUR CREAM! (light and non-fat are fine too) You can even add a few drops of your favorite hot sauce, if you want. Then just mix it all up really well.....
Heat in a covered dish in the microwave for about 2 minutes ~ stir and serve
Or.... you can always heat it up in a saucepan on the stove (but that takes longer and you need to keep an eye on it).