I think this is going to be a question for which you find a lot of differnet answers, depending on how each of us feels about what might drive us from our homes and for how much time we could be away from them.

My BOB has a three changes of socks and underwear. I have to hope washing is a possiblity beyond that time. The underwear is all synthetic, so it dries fast, if washing quickly is a possibility.

Otherwise, the clothing in my BOB is pretty much only one set, so I will have the stuff in my BOB and what I am wearing when i grab it and go. If I bug-in, then I have mmuch more. The clothes are is geared mostly toward winter. Long underwear, which can double as something to wear as other things dry. A pair of gortex rain pants, because I can wear them through almost anything. Outerwear to be worn in layers that should keep me warm enough below freezing, but on or two layers that I would wear at night in temps up into the 60s.