I incorporated calendula petals into my soap which includes calendula infused olive oil. I topped the same soap with calendula, blue cornflower, and rose petals. I just sprinkled them on. When I cut the soap, I cut it upside down so the cutting blade doesn't drag lines into the soap. The loose petals fall off when I cut the soap, leaving the petals that stuck well. I think it looks nice and doesn't really cause trouble when using it in the shower. When the petals get wet they get really flimsy and just go down the drain a few petals at a time. Hasn't seemed to plug the drain. Who knows, maybe my septic tank will be full of flower petals after a year or two. My husband won't touch that soap with a ten foot pole, but when I had a soap giveaway for my friends, most of those disappeared. They seem to like them. I haven't used lavender buds, though.