I'm doing cupcakes for a reception tomorrow. It is at 6pm. Can I decorate tonight and will they still be fresh? I'm using buttercream frosting.

ADefinitely I've done this loads of times and still fresh.

AI would, especially if your making a lot. I'd put them in the box then swirl on the buttercream. If your worried you could always brush with a bit of simple syrup before but I think they'd be ok either way.