GM as Host
The GM is also the host of the game. Whether the game is at the GM’s home or not, it is still the GM that is responsible for the game.
When new players want to join, they should feel welcome so that they enjoy the experience and want to return — make them feel at home. Make sure they know where the bathroom is, and where the phone is. Offer to get them something to eat or drink if you notice that they aren’t digging in.
People don’t care how much you know until they know how much you care.
Having enough chairs and table space makes it easier for the game to get going. If the table is covered with boxes, papers, and dirty dishes, players might feel like intruders in the GM’s home, instead of the important guests that they are.
Food and drink wouldn’t seem to be an integral part of a game, but even when playing, people need to eat and drink. As with any social gathering, especially one that lasts several hours, drinks and snacks are vital to keeping the guests happy. Even if the normal fare is chips and Coke, try to provide at least one healthy choice (like carrots or granola) for those who might take their nutrition more seriously (possibly from being on a diet).
Keep It Fun
As host, the GM needs to keep the game fun. After all, it’s a game, not a job. The players aren’t there because they have to be — they want to be. Whether fun, for the players, means saving the world, playing up the tragedy of a dying hero, or just goofing around with some friends, the GM should be the one that keeps the fun going. None of us can control another, however, and gaming is a two-way street just like any gathering of people. And if a game is considered a failure, i.e. not fun, the GM should not automatically assume full responsibility and fall into despair. But he shouldn’t feel that he has no accountability, either.
In order to keep the game fun, as a host, some GMs encourage costumes at their games. Although normally only seen at live-action games, and normally for fantasy and horror, they do occasionally pop up in superhero games.
Example: In the game where I played The Flash, the GM hosted a costume party at our game session the week after Halloween. I came dressed as The Flash, and made my entrance by running around the game room quickly. As it happened, I had a fifteen-minute hastily-scheduled Student Government meeting that same evening, in the next building over. I went in costume (since I didn’t bring a change of clothes), and to my surprise, it was the first meeting with several TV news crews present!
As host, a good GM looks after the needs of his people. When all the players are comfortable and happy, the game becomes more enjoyable.