Ckutalik asks us to elaborate on 3 essential elements as follows:
1. Name three “best practices” you possess as a GM. What techniques do you think you excel at?
2. What makes those techniques work? Why do they “pop”?
3. How do you do it? What are the tricks you use? What replicable, nuts-and-bolts tips can you share?
It's hard to narrow it down to just 3 "best practices" really. In surveying my own thoughts on the issue, dozens of best practices come to mind, however I'll try to stick to what I believe are the 3 most important.
1. The game is not about you, it's about your players
It's a hard truth to accept for many GMs. We all have our own philosophies on how the game should be played, but ultimately, the only ones you really need to worry about impressing are your players. That is not to say that you fudge dice rolls, or give into unreasonable player demands at the table. Rather it means keeping your focus on what the players want to do in the game as opposed to what you would like to see them do.
This especially rings true in preparation. There have been countless times when a GM has sat down with his players, having prepared a nice little adventure for them, only to have them do something completely off the wall which derails all that preparation. We hear about these things happening at the table all the time, and true enough, they happen at my own. It's part of the game. You have to learn to roll with it, because it's never going to change as long as you believe in not restricting player control over their characters.
This is where the sandbox style really shines, however, because you are providing a world with which the players interact, and the choices they make should always matter. Resist the urge to railroad players into certain situations. Present the adventure hooks for them, and let them take it in the direction they choose. This is going to require improvisation on your part as a GM, but if you're remotely considering sandbox style play, you must accept the fact that you will likely be improvising...a lot.
Make the world around your players a living and breathing thing. There are NPC motivations outside of what your players are involved in at a given time. Their characters can't be everywhere all the time. Maybe they have a few options in the beginning, but they won't know the results of their actions until things are played out. For example, they have option 1, which is to raid a nearby set of ruins overrun with undead, or option 2, which after some investigation by the players, results in their foil of an assassination attempt. If they pick option 1, don't forget about option 2, and let the consequences of their choices take place. Let that major NPC get assassinated because the players didn't take that hook.
Know your world, and write down notes on events surrounding it. These don't have to be detailed pages and tomes of useless information that may never come up in play. Just a series of simple bullet style notes, preferably keeping it in line with your campaign world calendar. Those particular events in which your players actively chose not to participate in, should happen. The ones in which your players took the bait of a hook should be saved and the results determined by their actions in the game. Doing this, they will quickly realize that their actions have consequences, and will respond accordingly.
Ultimately you want your players to have fun, and have a strong desire to return to the gaming table and continue. That's what it's all about. If your players prefer detailed railroady storyline games over an open-ended sandbox style, then give them what they want, or find a group of players whose play style fits more in line with your own. Don't force players down a path they don't want to take in play style, because the results will often be complacency at best, or downright apathy at worst.
2. Stay Organized
I am the most unorganized person you'll ever meet really. My organization skills in general entail trying to remember if I laid that notebook under the bag of Doritos I've been working over, or with a bunch of other notebooks piled on top of my printer. Still yet, I try my best to keep things organized when it comes to the RPGs I run.
I can't stress enough how important it is to have a campaign notebook. For me, this typically means a traditional 3 ring binder with dividers, document protectors, and various useful in-game documents. That said, your campaign notebook can entail a number of different options. Find whatever is best for you, and run with it. If you can keep things organized on a laptop, or on a site like Obsidian Portal, use those methods, but try your best to stay organized.
So, how do I do it? As I said, I have a 3 ring binder I use, tabbed with document protectors. I have a section for maps, random tables and charts specific to the area the players are in, and a section of notes for the game.
I have stated above how important improvisation is in sandbox gameplay. I tend to use a lot of tables and charts which I can quickly refer to in a jam. These include NPC name generator tables, inn and tavern name tables, random trap and trick generators, etc. These are particularly handy because they allow you to focus your creative energies into important stuff, like the game, rather than having to spend mental energy to find a clever name off the top of your head for a NPC or location, which may end up sounding stupid (we've all been guilty.)
In my maps section, I usually keep a handful of maps I have either made, or found online. There's usually a mixture of both. Some of these mini-dungeon areas are keyed, while others aren't, but the idea is to whip one out in a jam when the PCs go off the beaten path. This way I'm not completely caught off guard. I know, for example, in general where my players are on my hex map before each session. I will then prepare a few maps and encounters for various locales in and around those hexes. Nothing too fancy, just enough to give me something should they wander off from what I perceive to be their goal at the time. Best of all, I can always use those maps in other areas later if need be.
The notes section is probably the most important section of the notebook. I have a campaign log which I keep, an item spreadsheet which lists who has what item, where they got it, if it's been identified and the items known and unknown properties. I also keep a small chart to document xp to help me calculate everything at the end of a session.
My campaign notebook is like my GM bible for the game. A good, well kept campaign notebook, will bail you out of sticky situations, and just make life easier for you as a GM, which in turn, will make things better and more enjoyable for the players.
3. Don't over-prepare
Don't spend too much time in preparation, and stick to things that will directly involve your PCs. Do you really need to write up 3 or 4 paragraphs of notes on a temple or inn your players may never visit? Improvise many of these things. Stick to what's important for the upcoming sessions. Yes, this can be, more or less, a fly by the seat of your pants method, but that's the fun of the sandbox. You're discovering your world along with the players.
When I start a new campaign, I like to take a hex map, key out several locations of interest, without detailing them too much, a brief set of notes on major NPCs in the area, and their motivations, various secret groups and organizations, a very brief overview of the political climate of the area, etc. These don't have to entail hours upon hours of needless preparation. Just a few notes, allowing you to focus on really preparing the important stuff, like areas your players might explore. Throwing up a few one page dungeons to get things going is a good idea.
It's very easy to find yourself spending hours preparing for scenarios your players may never encounter. I've done it myself, and in many ways, it's simply unavoidable, but try to limit the time and energy you spend on your campaign into what directly involves your players in the current session. Trust me, some of the best moments at your table will come through improvisation and just winging it. Just ensure you take good notes (or keep a campaign log as I mentioned in point 2), so you can keep things organized.
Some of these methods may work for you, some may not, and many of you are probably already implementing these methods in some form in your own games anyway. There simply is no absolute best way to GM. It would be a pretty boring world if that were the case. Still yet, we all have techniques and experiences to draw upon, which can make the job of GMing easier if we actually take the time to read and learn from others.