How are you going to distinguish that clean underwear from that um not-so-fresh underwear? Well, MSNBC has a great tip on reusing an old pillowcase to store dirty clothing in your suitcase.
If you happen to have an extra or unused pillowcase lying around, guess what! You’ve got a dirty laundry bag for your next trip. Assuming it’s not a cover for a body pillow, we say go for it. Why anyone would want to burn $20 for a travel laundry bag is beyond me, and there are better things to do with your money. (Can someone make the case for me?)
A separate laundry bag separates your stuff from the Toms you just muddied on a four-day trek. Shoes, on the other hand, are best kept in a plastic bag because of the dirt they tend to accumulate. The best part is that no one has to know what kind of sheets you actually sleep in.