How to be a good DM

I keep seeing this sort of thing crop up, so lemme give you a couple of quick pointers on how you, too, can be a good DM, Lawful Indifferent style.

1) Do what your players want. Don't take it out of context. It means that you should do what your players want, because otherwise, they're not going to be happy. Unhappiness breeds discord, and nobody has to play in a game that they like. Does this mean that you have to give them everything they want in a game? No, that's not what I said. I said you should do what your players want. If they want to run a differently themed game than what you want, then run it. If they want to have a high-combat game, then run it. If they want to have a game where everybody's frogmen and they spend their time hopping around and converting people to the High Hopper, do it.
2) Make your players work for what they want. Doesn't that sound contradictory? It's not. Make them work for what they want, and they'll thank you for it later. Imagine that you spent all day working outside in the heat, getting a sunburn and blistered hands and scratched up knees, and finally, your backyard looks great. You earned it, and you probably love it. You earned it! Great job. Imagine that instead of doing it yourself, you got your kids to do it, or hired somebody to do it for you. It might look even better, but you know that it wasn't you, and there's nothing to be proud of. All games are the same way. If you win without hardly having to try, it's unsatisfying. If you win by the skin of your teeth, it's awesome.
3) Run something different. "But my setting IS different! My dwarves don't have beards!" Shut it, you hack. Do something different, really. Don't rely on standard fantasy tropes unless you're doing something really cool somewhere else, like playing a new system. Or maybe you really do love the standard fantasy elves and stuff- but you decide to make it like Ancient Babylon, and everybody has conical hats and wears pleated leather skirts and sandals and the world is a disk surrounded by a literal firmament and sometimes it cracks and causes monsoons and stuff. Be original.
4) Do what you love. This isn't contradicting any of the other ones either. If you're having a great time, even if you're out of your comfort zone because it's not what your players want, your players will notice. You're the biggest dictator of mood and theme in the game. It's a weighty responsibility, but that's the way it is. If you don't love what you're doing, you're killing your game. Don't be the grumpy DM that's constantly killing people out of some sort of grudge. Love whatever you're playing, even if it's not what you personally wanted to play (see step 1).
5) Don't plan anything. Ever heard the phrase "No plan survives contact with the enemy?" It's always been true, and always will be. Whatever you had planned, throw it out the window. Run a game by the seat of your pants, with maybe (maybe) half a sheet of regular lined paper in front of you for names. The best ideas I've ever come up with were roughly 15 minutes before game time. I wrote some names down, had a basic idea of what was going on (in this case, we were playing Dark Heresy and the players were investigating an apocalypse-world that had been overrun by, essentially, dinosaurs), and then we went from there. Everybody had a blast.
6) Do your own thing. Don't let anybody tell you how to run your game (including me), and take every bit of advice with a grain of salt (including this, if that isn't enough of a paradox for you). If you love running one kind of game and won't budge, cool. If you just want to run a bunch of combat and everybody on the internet is telling you to roleplay till it hurts, whatever. If you get chills down your spine at the thought of handing out +30 Greatswords and slaying Dragon Gods and every dungeon is a Monty Haul, that's sweet. Remember how I said that if you're happy, the game's going to run well? I wasn't kidding. Do what you like, and good gaming will follow.