In advance: Use royal icing to make about 100 tip 24 swirl drop flowers with tip 2 dot centers. Make extras to allow for breakage; let dry.
Also: Make cookies. Prepare and roll out dough. Cut 1 heart with smallest heart cutter and 2 rounds each with small, medium and large round cutters from set. Bake and cool cookies.
And: Use tip 2 and full-strength royal icing to
outline heart and 1 of each size round; fill in using thinned royal icing. Let dry 48 hours.
Layer pairs of round cookies with buttercream icing; attach drop flowers around edge with icing. Using royal icing, stack and secure cookie pairs; attach upright heart to top and surround base with drop flowers.
Drop flowers are a great way to add flowers quickly. Pipe drop flowers in buttercream directly on your cake, or pipe in royal in advance and place your flowers anywhere. Flowers will be sharper in definition when piped in royal.