There's no need to share your pricey salon shampoo. The next time you're staying at a hotel or a resort, remember to take away the small toiletry bottles. The sample sizes are perfect for guests.
Or stock up on travel-size toiletries on your next trip to the drugstore or at minimus.biz, a website devoted to mini products, including toiletries. A new bar of soap, shampoo, toothpaste, a toothbrush, a razor, and body lotion should cover anyone's basic needs.
To keep track of towels and washcloths, provide a different color for each guest so everyone can always identify his own. When the guests drive away, wash and store the towels (along with sheets, a light cotton blanket, and a heavier comforter for cold nights) until the next visitors arrive.