When they arrive, go to the door to greet them. Shake their hands and make them feel that you are pleased to see them. Then introduce them to some of the other guests. Think of a topic they have in common and get them talking to each other before you move on. If they feel welcome, everyone will be more relaxed and ready to have a good time. You can use lighting to create a different mood, or move your furniture around to create more space. Decorate your room and play some music in the background because it will help people to relax.