Confession time: I'm not the world's neatest person! In fact, my mother always used to claim my t-shirts were hungry, because I liked to feed them when I ate! But I like to travel with hand luggage only ('carry on' as those in other parts of the world call it) and I need to look professional when travelling for work. So I'm going to let you in on my two chief weapons, baby wipes and travel sized lint rollers. And a stain removal pen. My THREE chief weapons are surprise, baby wipes... (etc :P)
Baby wipes are remarkably effective stain removers - they'll get just about anything out of anything. But on the rare occasion that doesn't work, I have an instant stain removal pen. In the US you can get Tide to go, which I've read good things about. In Australia you can buy these on ebay, or occasionally you'll find them in shops that sell things like "Hollywood tape" and other handy items associated with being a woman like gel insets for silly shoes.
My other weapon is a mini lint roller. I ran out of the 3M one I bought I think from the Container store in the US, but was delighted to find they sell them at Bunnings for $2 each (no point linking as Bunnings have yet to join us in the 21st century and start selling things on the interwebs). I have two pugs, aka constant fur-shedding machines, not to mention a cat, and yesterday I opened the package of a brand new black cardigan I bought on line, to find (I kid you not) it had pug hairs on it already. THEY HAD MIGRATED THROUGH THE PACKAGING!!!
I wear a lot of black while travelling - it's the best for minimising the visibility of anything unfortunate, but it shows up fawn pug hairs like they're giant genetically engineered glow in the dark mammoth hairs! The lint roller is a must for staying professional - and it's also great for stray hairs, furniture that was shedding lint, scarves that were shedding fibres - the list goes on!