Don't joke about a thing too much or you'll have to write a post for it!!
Sometimes I think about the fact that when Simon comes on board Serenity, he is carrying a small leather briefcase, his red medbag, and a suitcase that looks to be "carry on" sized. This is all he has (aside from the cryobox). What's in there?
Long heavy coat (Out of Gas)
Six vests: Maroon and gold (Shindig, Safe), Light blue (Ariel, War Stories), Gold (Train Job), Maroon (Safe, Our Mrs. Reynolds), Bronze (Bushwhacked, Ariel), Brown pattern (Out of Gas)
Shirts: Light blue (Ariel), Black (War Stories), Probably at least 2 white shirts, Collarless navy button up (The Message), Collarless pale button up (Safe, War Stories), A mysterious purple shirt he never wears (Safe)
As seen in the Pilot and Jaynestown, he wears undershirts--four? Five?
How many pairs of black slacks? Probably at least one.
Presumably underwear and socks and sleepwear
I'm personally going to say that he brought his purple "War Stories" sweater with him because it does match his sort of preppy style and it doesn't feel like the other sweaters (Trash, The Message) that read like Wash hand me downs
At least three books (Safe)
Probably personal grooming supplies (he's cleanshaven after all, and appears to have a pretty consistent and neat swoop to his hair)
I'll throw in some River clothes!! This is, after all, partially inspired by @tamsiblings post about River's wardrobe. I think the yellow shirt from Train Job makes sense, and I'll include the bike shorts. She was a dancer and these make sense as something she'd wear and feel comfortable in even after two years of rapid growing.
idk this seems like a lot to fit in that suitcase. I'm not quite at the point of obsession where I'm going to try and replicate it irl but it just seems like he would have needed a bigger bag.