I often make my flowers in advance, on cocktail sticks, using cell buds, so easy to pop them in, and out again without damage to the cake! Use a dap of royal icing to secure them. You can also get this stuff called safety seal, but having tried it, I’m not a fan, obviously you let the customer know re the inedible flowers on the cocktail sticks! Hope this is helpful? 😊 I’m sure you will make the cake look stunning :)