The longer you travel, the more likely you'll need to wash your clothes. You can:
Use a laundromat (if available) - common in Europe, but not so common in Asia and South America
Use the hotel's laundry service (often expensive)
Pay some locals to wash them for you
Wash them yourself - e.g. in the hotel bathroom (some don't allow this)
Note that if you are charged by the kilo and the clothing is already wet, you'll pay a whole lot more. Allow the items to dry out first, or negotiate a lower rate.
The cheapest way to do your laundry (albeit not the most thorough) is to do it yourself. If staying at a hotel, make sure this is not against the rules.
In the bathroom, fill the sink or bathtub with water, some sort of soap (or shampoo, body wash, laundry detergent), and your dirty clothes. You can use a universal sink stopper or just a dirty sock.
Let it soak for about 15 minutes
Swish the clothes around. Scrub each item individually by rubbing the cloth together, concentrating on areas such as the armpits and stains. Apply additional soap as needed.
Rinse each item under a faucet (e.g. the shower) until the water runs out clean, not soapy.
Wring the excess water out of the item.
Hang up your clothes: outside is best or use a portable clothes line. Try to let them dry as long as possible, e.g. overnight, or if you're in the same room for several days, for a full day..
You can also try using a hairdryer, if available, but be careful not to allow fabric to become too hot (which can cause shrinkage, or in extreme cases, scorch.)
If your clothes are still wet, pack them in a separate, plastic bag.
This travel topic is an outline and should either be merged into an appropriate parent topic or else developed further. It has a template, but there is not enough information present for it to be of real use. It was last edited on 2011-10-1 and will be merged or deleted if not modified for one year. Please plunge forward and rescue it!