It kind of depends on the trip...
How long will you be on the road, and what are your plans?
I'm a minimalist; when it comes to clothes...
a pair of jeans can last two days pretty easy, and the same pair that I wore on the trip out, can easil be used for the trip home.
Tee-shirts, drawers, and socks get changed daily...
Depending on the climate...
A long-sleeved shirt or two might be necessary... they can be worn multiple days.
riding boots are worn, a pair of sneakers are brought along to double as slippers
Of course:
Raingear
cellphone and charger
laptop...

basic toiletries... Nothing more than the minimum requirered to scrape the crud off!
Since I'm a Type I diabetic; I've got to carry enough medical garbage with me to annoy a lot of folks...
I'll have infusion set changes, BGM sensor changes, BG meter supplies, a supply of emergency syringes, etc... it comes with the territory!

Oh! And I NEVER travel without food! I'm partial to granola bars and gummy bears; the stuff that's sure to stop a hypoglycemic episode in it's tracks! :thumbup:
And water... hydrate enough to stay healthy; NOT enough to force extra pitstops!