I was wondering about different textures i could use with icing, instead of the smooth look what else would be good for Birthday cakes, Something fun for teenagers , Thank You!

Smooth top and combed sides
Sprinkles on the sides
Home-style iced sides

Sotas makes a nice texture too (if you want to consider it a texture rather than a technique!)

Sotas: http://www.wilton.com/technique/Sotas

I don't consider Cornelli/Corneli Lace a texture, but if it covers the entire cake, it sort of is!

http://www.wilton.com/technique/Cornelli-Lace

I have a cake friend. She uses a damp terry cloth. Looks very good.Also seen different textures of sponges used. Using your spatula.