In a bowl, whisk together powdered sugar and milk (or liquid of choice) until smooth & drizzly.
Optional: Add vanilla extract to make a vanilla icing, or use any flavoring you like. (Or no flavoring!)
Start with less liquid for a thicker icing, or add more liquid to make a thinner powdered sugar glaze. If the texture gets too thin, whisk in powdered sugar 1 tablespoon at a time until you get your desired consistency.
Add colour of your choice to decorate as necessary