One of the things that makes those cookies is the frosting. I have had lots of people request my sugar cookies which are just sugar cookies but I think it is the frosting that keeps them asking.
Frosting
1 stick margarine
1 tsp vanilla
2 T milk
3 c powdered sugar
Gently mix until you won't throw everything all over the counter then whip it. I actually just dump things together so if this is too dry add a touch more milk and if it is too wet add more powdered sugar. I think the secret is whipping it.