Usually friendly, enthusiastic students tend to create a friendly, positive atmosphere. In these cases, families often include students in social activities, family outings, etc. A small gift such as chocolate, ice cream, or a dessert to share at dinner always makes a nice gesture towards your family. If you have a good relationship, you might volunteer to wash dishes or cook a special meal. Some past participants suggest bringing a small present from home - hard candy, music cassettes, unusual local spices, lighters, etc. with logos of sports teams, pictures of your home, hometown, etc.
Generalities are problematic, especially when discussing homes which are all unique.
For virtually all programs, your housing payment goes to the school and from there to the family. If there are misunderstandings, talk to the housing coordinator at the school. Do not loan money or make investments. Families do not refund missed meals or weekends out of town. Appreciate that food and utilities generally cost more abroad than at home and foreign hosts are paid relatively little.