Bring a gift: A gift shows your host or hostess that you appreciate their kindness and generosity. The gift doesn't need to be expensive to make its point. A collection of specialty soaps, candles, hobby helpers or edible delights can be just right. Do consider the number of nights you're staying when deciding on your gift, being mindful of the money you're saving by not being in a hotel.

 

Help Out:  No matter how close your relationship, your stay does place extra work on your host.  So ease the load by helping clear the table after meals or washing dishes, making your bed, and keeping your belongings tidy. Treat your host to a meal - or more than one, depending on the length of your stay - whether at a restaurant or with your own culinary skills.
 
Ask about your hosts:  Show an interest in their job, hobbies, accomplishments, children, or even pets. Whatever you do, don't talk endlessly about yourself; it will eventually become boring, and your hosts will resent having their time monopolized. On the contrary, interestingly, when you ask about others, letting them talk about their strengths and interests, they will feel you're a good conversationalist and enjoy having you in their home! 

Give your hosts some "space":  Don't assume your hosts can - or want to - spend all their free time with you.  Planning some activities independent of them gives all of you some breathing room, as well as conversation starters as you each share the highlights of your day.

 

Let your hosts get to sleep:  Remember, your hosts aren't necessarily on vacation just because you are.  Be sensitive to their routine or work schedule, and don't keep them up late talking if they get up early. 

 

 
Remember the "fish rule":  The old saying goes that both fish and guests start to smell after three days!  While your relationship with your hosts may outlast that, it IS important that you don't overstay your welcome. Better to have them wishing you could stay longer rather than counting the days 'til you leave!