For me, the beginning and end of advice on how to be a decent/good/better GM is communication. I've been saying for a while that this is an area of advice that is sorely lacking in game books. Part of this "advice" comes from taking communications classes in college (and sometimes listening), while part of it comes from way too many years of being a gamer.
Communication in a gaming group assumes a few ground rules.
- Everyone at the table is a grown-up. This might not apply to those who run groups with kids, but I am sure that you can find an application of some of what I'm saying here. Everyone at the table is a grown-up is two-fold: it means that everyone at the table/in the group acts like an adult, and it means that everyone at the table gets treated like an adult. This means acting responsibly but also means not acting passive aqgressively. Grown-ups are able to actually bring up and discuss problems in a mature manner. Problems can vary from comfort level of what is happening in the campaign, punctuality, personal hygiene of the people in the group, etc. You can't have communication if everyone isn't willing to communicate. That's OK for some people, and some groups, but it's only going to be OK for so long.
- Talking About Stuff is OK. Gamers, we're a varied bunch and there is no gamer monoculture, as much as some might want to make people think otherwise. We all have different interests, different backgrounds, different likes and dislike. We all have different comfort levels about the inclusion of sex and violence in our campaigns. If the content of a campaign is moving outside of your comfort zone you should tell the GM about it. Maybe not in the middle of a session, unless the group is on a break or something, but in-between sessions, or directly before or after getting together for a game. If you're not comfortable talking about this with the whole group, just take the GM aside or send an email. Letting an uncomfortable situation fester will just make things more and more uncomfortable, and no one will know why things are uncomfortable. It's better to just clear the air and talk about things.
- You don't have to all like all the same things. I know, I said this in point two. It needs emphasis. It's OK to like different things from each other. If you don't like the play style, or type of campaign that the group is doing. Say something about it. This does lead into my next point.
- Gaming is a group activity. Shocking, I know! Sometimes you have to take one for the team so that everyone at the table has fun. It isn't about you (whether the you in question is the GM or one of the players), it is about the group. This doesn't contradict the above point, however. What this means is that a gaming group is a balance between the needs of each person at the table with the needs of the group. How you determine the "group" is up to, well, the group. It can be that everyone at the table has to be happy all the time (which is going to mean a lot of compromise from the individuals at the table) or the majority is going to have to be happy most of the time, on a semi-rotating basis. The latter is my preferred style, and it takes a lot of juggling on the part of the GM and it also takes open communication channels. That's a lot of work, and it's not for everyone.
- Don't shut down people, or shut out attempts to communicate. People are people, and you have to treat them nicely. If you want to have open communication that means keeping things open. "That's stupid." "Shut up." "Why would you think that?" and all their variations shut down communication between people. Don't use them. Listen and be open, even if it actually is something that you aren't interested in hearing about. It's important to the other person and sooner or later it will be come important to the group.
- Talk for f*ck's sake. Communication means communicating. Out loud. Using words. Never assume that the people at the table know what you're feeling. There might be telepaths in the game world, but they aren't at the game table. Nothing derails a gaming group like someone trying to get their way in a passive aggressive manner. Put your issues out on the table and discuss them. Keep in mind, however, that not all issues can be overcome by the group. That leads to...
- Probably the best piece of advice to ever come out of RPG.net is No gaming is better than bad gaming. This is the hard thing for a lot of us, but if it gets to a point where you cannot talk things out in a group it is better for everyone involved to just walk away. Yes, I know. Many of you are saying "But, I only game with my friends." Yes, and is it really worth losing friends over gaming? Regardless of what some may think, friends do not have to do everything together. I can't think of anything worse to lose a friend over than gaming. Having sex with the same girl? Sure, I can see that. Pretending to be elves? Not so much.