Luggage is a good storage space as mentioned. The trunk of your car will hold quite a bit also.
It is a good idea to stay away from black garbage bags. When I was a Project Linus coordinator, it was tempting to use those for blanket delivery. Instead I choose white bags and used a half page computer label to identify the agency and the contents. I was so afraid that someone would toss a black garbage bag.
Best wishes on the whole ordeal!