I'm considering selling flowers by post. Does anyone have any care suggestions for preparing them for transit?

My main concern is with Roses. Once I receive them from the wholesaler should I cut and condition them, then re-wrap them up? Or is it best that I leave them and send them straight on the next day - as the rose head will already be opening by that afternoon if I water them well. I'm concerned they will have already wilted by the time they arrive.

I'm fairly new so be gentle. Thanks for reading.