I am in a 16’ fiberglass trailer, about the same sq ft as a good size modern camper van. Here’s what I do for clothes, but then everybody has to do what is right for them…
I try to stay away from cotton t-shirts. I prefer the active wear stuff that wicks moisture away, is super lightweight and layer-able, easily hand washed and dried if needed, and if not, dries super quick at the laundromat. They also roll up smaller than bulky cotton t-shirts.
For pants, up until recently, I was mostly wearing leggings. A lot of the qualities extolled above apply to these, too. For shorts, active wear. Same as the other stuff. One pair of boots, one pair of closed shoes, one pair of slippahs (Hawaiian pidgin for flip-flops), and one pair of wool felt slippers. Lots of lightweight not-cotton tank tops to wear under other stuff. The other stuff is the above mentioned t-shirts, and at least a couple chiffon tops. They also hand wash and dry super easy. They roll up super tiny. Lots of not-cotton undies, and two bras when I’m being reasonable. Socks. Just enough, not too much. One hoodie jacket. No actual coat. Two or three cheap comfy dresses that can take being rolled up. Pareos — Very versatile things! I also have the luxury of having three real sets of PJs.
Right now, for reasons I can’t quite understand myself, I have two pair of jeans. I love them when on me, and really dislike washing and drying and storing them.
As I’ve said on this forum before, I don’t carry towels. They’re too big and bulky and make no sense, even in a stick and brick house. I use pareos for towels (and dresses and skirts and shade and privacy screens and beach blanket and nap covers and market bag and table cloth and even curtains in my little camper house).
I have a few more items, but they need to go. Because the jeans take up too much space!
If I had to cut my clothing amount in half, I’d still be fine. It’s just nice to have some variety since I can. When I boondock out on my own in warm weather, I practically live in pareos and slippahs. My weekly wash pile is negligible.
Just think of the through-hikers on those famous long trails. They carry everything with them. More than 1 full change of clothing would be a burden. So take what you have room for, but choose each piece carefully. Good luck!