This is my seashell cake. I used plastic chocolate/soap molds purchased online and gum paste for the shells. I first used a brush and dusted the inside of the molds with luster dust so that the gum paste would not stick to it. Once I pressed the gum paste in to get the shape I took them out of the mold to dry. I cut around the rough edges with an exacto knife while still wet. Once dry I used a fine filing block like you use on your finger nails to finish all of the edges nice and smooth.