I have made something similar when I had a valentines party. I bought a piece of styrofoam and cut it in the shape of a heart. It was pretty thick. I'm sure for a tree you might want it in the shape of a cone. I covered it with foil. I glued the heart on to a foil platter upright. I dipped my strawberries in white and dark chocolate and let them get cold. I inserted toothpicks into the heart and put the srawberries on them. I filled it in with dried dipped apricots and silk leaves from a florist shop. It was the hit of the party.