When you get up in the morning write down everything you used, 1 wash rag, tooth brush, tooth paste, soap, hand towel, etc. Then pack up what you used in a box or plastic bag. Lay it aside and see if you use it again every day for a week. See if you can use something to do more than one thing or use a smaller portion/container. Pack these items as you would if they were in the van. I have a Tupperware container that is 12" x 16" x 6" that holds everything I use daily plus all my personal hygiene, first aid, medicine, phone charger, flashlight and batteries, extra glasses, etc. If I don't use something for a couple months I consider getting rid of it. Summer time I cut my hair short so I get rid of my hair brush, that gives me space for sun screen as an example. A weeks worth of clothes and two weeks of under clothes. Hit the laundry every 14 days as BLM rules usually require a move. 2 or 3 milk crates handle all my clothes, and shoes. Jackets are stored flat under my mattress, as well as extra bedding. Basically live in your house like you will in your van. Use the same totes, boxes and crates that you will be using in your van and see how it works. Only take things you will use, if in doubt leave it out (see how often you really use it). It won't do you any good if you cannot find or get to it and stores are everywhere if you really need it, space in a van is worth more than a lot of other things you don't use often.