A new tradition has been hatched for the Tuttle family: Every Easter, we're to go to Florida for an extended family event. Lots of good food, cocktails and of course, some egg hunts - one for the kids, one for the adults. This year, my sister-in-law's birthday happened to fall on Easter weekend so as a present to her, I made the above chocolate cake.
Since I was flying, I didn't want to assemble the cake in New York and have to transport it in its final state. I cut the flower stems to a short height, wrapped the ends in very wet paper towels, then in plastic baggies and hoped for the best. The flowers ended up in Florida just fine. I took off its wet soakings and put them back in some fresh water.
When selecting flowers, chose a variety of shapes and sizes. Pick one color/hue and make sure that that color appears somewhere in all the flowers for the most cohesive looking arrangement. Start by placing the largest flowers you have on the cake, and work your way down to the itty bitty flowers. The latter can be used as filler between flowers. The lilacs used here were also helpful for providing a little edge draping.