Red Berry Wreath What Kind Of Frosting Should I Use?

What kind of frosting should I use? - red berry wreath

4-H, I make a cake decoration. No matter what kind of cake, (the house / box mix, chocolate / vanilla, etc.), while creative decoration.
The bread I chose a touch of bread as a Christmas wreath - pine cones, holly berries, belts, etc., decorated decided it like a crown, and I'm going with red velvet cake does not appear, a green crown.
My question is: What is the best way to use ice on it? I want something spreadable, but not fluently. So dear not too thick, either. Thanks in advance!