I have used Luggage Forward several times in the past. It is especially nice when sailing on a transatlantic. We would visit port city for several days before cruise but didn’t have to lug around all our our luggage.
If I remember correctly they will pick up from your home about 1month before sail date. You fill out customs paperwork and schedule a pick up. Then when you board ship your shipped luggage arrives to your stateroom.
Hope this helps.