I really like using royal icing to decorate cookies. You can find my tutorial on how to flood cookies here.
For easter, I created these fun bunny cookies and a few butterflies:
For the bunnies, I flooded the white first. Once it was mostly dry, I used pink royal icing to make the ears and nose. Finally, I drew on faces using edible food markers (I had to assure people it wasn't a sharpie).
Easy and professional looking! Again, I love royal icing.