You can take your wedding dress, morning suit or bridesmaid dress as part of your hand baggage as long as it does not exceed your hand baggage allowance (i.e. number, size and weight of bags).
Your bridal shop should be able to give you expert tips for how to best pack and 'refresh' your wedding outfit at your destination.
On long haul flights - ask your cabin crew if there's any space to hang your wedding dress or suit and they will do their best to help, though there is limited available hanging space on board, especially on busy flights.
On short haul flights – you won’t be able to hang your wedding outfit as there is no available wardrobe space onboard. Make sure your outfit is packed appropriately into your hand baggage.