If live rock is included make sure you keep it moist/wet to minimize the die off of beneficial bacteria in the rock. The sand make sure rinse in saltwater to get as much of the junk its accumulated out. If the funds are there to buy new sand that'd be the best route. If there are fish and corals that need to be moved into the new tank right away it be best to get new sand cause the exsisting sand bed will be disturbed during the tank move and could potentially cause a cycle. If there there is no livestock going into the tank right away use the same sand give it a good cleaning and let the tank sit for a week or two to make sure the tank is stable.