I'm open to suggestions.
I cut a hole in the top of a banker box(used to store files) the size of the container. It sat in the hole perfectly and never moved on a 1 hour trip.
The way I do is that I decorate my bouquets before, as well as the beautiful cupcakes. And once I get to the deliver place I put them on their bouquet holes or cases. For sure I arrive like half an hour earlier so I can give them on time. By the way the cupcakes I drive them on their boxes so they don't move and split all over.