What is a one-sentence summary of the following article?
Even if you're not eating at your host's home, offer to purchase the groceries. Remember that your hosts have probably already been shopping for extra groceries and spent a considerable amount of time and money to get ready for your visit. You could either bankroll their next supermarket trip, or offer to go out and buy things for both yourself and for them (ask them for a list). Don't be embarrassed about asking whether or not it is okay to do your laundry at your host's place. They understand that after a few days you'll have dirty underwear. Ask your host when the most convenient time for you to do your laundry would be, emphasizing that you don't want to cut into the household's normal routine. This doesn't mean crowding the host out of the kitchen, but instead it means collecting plates, carrying out dishes, offering to wash up or stack the dishwasher, cleaning off the counters, and taking the garbage out. You could even offer to cook a meal or two yourself.

Summary:
Offer to make contributions. Do your own laundry. Offer to help at mealtimes.