Concrete pine cones. The fine rustic pine cones in the concrete, I cast in latex molds. The molds I have purchased from Pandurohobby. When I had filled the molds with concrete, I put them in a bucket with a little sand, to support them, so they are not overturned. Recipe 3 parts of sand, one part cement + water, stir to form a thick porridge. Remove after concrete dries for a few days.