I hope it's ok that I don't put links. I think the ones that are from blogs should be easily found

• Lazy GM - creates a habit of loosely planning the plot, so you can have a bag of things to use, without having to railroad, and changing the plan because of players' actions doesn't hurt
• don't plan plots, plan obstacles - when you get into the habit of thinking what could be an obstacle in a situation, you don't have the game to go this or that way. You only switch between applicable obstacles
• onion plots - "who needs what, what for, but they can't because of what". That way coming up with a follow up is easier
• run combat like a dolphin - mainly, remember to describe things. Yes, I have to actively remember about doing that
• stars and wishes - to me this is the most constructive form of after session summary. If I ask "what you didn't like?" (roses and thorns), to me it is not clear how to improve. When it's about "what you wish/wished for?" it's much easier to decide whether there was a problem with expectation management or maybe a cool idea that I passed up
• yes and+no but - mainly, even if we are playing a more trad game, I don't ask for a roll if I (the plot, of course ) need the thing to happen. I ask for it to answer an additional question "will the character do this well enough to uncover additional details?". Unless we are in a simulationist wounds&initiative combat, the roll to me is a plot device, not plain success/failure

And thing I came up on my own but might be only because how my mind works:
Do split the party
What I often do is present the obstacle, ask around what the characters are doing after learning that. Then I choose the sequence that I feel has the most meat on it - story to be told and go one by one. Even if an idea surprises me, I've found that by the time another player rolls their dice I already know what to do with the previous one. And when scenes have fewer participants, it's easier to manage spotlight and have lower stakes per scene

This isn't from sly/Ginny/colville etc, and maybe a weird one, but for my table: "don't be afraid of a little silence". I would fear it, fill it with whatever I could, and that hurt the pacing, the quality of descriptions, and intraparty RP. A great improvement was achieved by talking less

Wow, you guys are actually giving really good and useful advice.

I was about to comment “When one of my players asks whether they can do something completely unreasonable I look at them, roll a D20 openly on the table and without checking the result, say ‘no’”

But now I just feel bad

The players won't care about how pretty you make your maps. Make them functional and ugly, and you'll save up so much time for other prep.

I found a map-making site that is, let's be honest, shit. The maps it makes can only ever be "good enough", and never great. This means I don't waste time trying to make them great, and can actually finish the dang things. Plus, if the players decide not to go to the noble manor, then it's no big loss.

This idea goes for a lot of the game, actually. If you spend less time on the story, then it's no big loss if the plot takes a tangent. And they probably weren't going to be as invested in a forced narrative as they would be for something more organic.

When I first started DMing as a kid, my dad told me the best thing I could do to prepare was just know the whole world. He then told me about an adventure he was running where the players, for literally no reason, started digging in the middle of a tunnel. There was a whole dungeon set up for them ready to explore, and they went 50' into the tunnel and started digging their own tunnel.

I think better advice in that situation is to find players who want to play the game you're running. It might be fun to make a tunnel-exploration campaign, but I'm running that dungeon over there. We'll do the tunnel thing another time.

Also, to rephrase your dad's advice, know enough of the world to be able to add shit where you need to. I don't even know if the world is round, but I don't need to. If the players are in a church, I'll make sure to know the popular religions in case I need to roleplay as a priest.

I don’t even know if the world is round, but I don’t need to.

The players will find a way to make you need to.

Use every opportunity to turn planning into information gathering.

I try to use every opportunity to stop the planning "phase" of the game and go to the information gathering before continuing the planning. This can be pretty much any unknown that the characters bring up, like some if -statement in their plan, some fact they are unsure about etc.

The information gathering might be anything from a simple skill check to a full adventure and after that we go right back to the planning.

This has removed a lot of planning hours that wouldn't have had anything to do with the situation they are going into.

No, the world is enormous and you only need to worry about a small part of it. There is literally nothing over there, and no reason you'd want to go there. The game is over here. Leaving this area is the same as leaving the game, which you are free to do.

I was about to comment “When one of my players asks whether they can do something
completely unreasonable I look at them, roll a D20 openly on the table and without
checking the result, say ‘no’”

Oh, GM Fiat... I always preferred the GM Camaro, but you do you...

Let them look cool.

Too much time is spent working around the players’ abilities to make a fight challenging. Some fights should look hard but have a player ability break them. Let them use the powers they earned.

This slightly ties to the idea that the game is not the players against the DM, it is the players against the world, while the DM narrates.

For depth in world-building I use a rule I call "Y-cubed". (I got it from somewhere else but can't recall the source anymore.)

For every detail you make, you ask the question "Why" three times.

So a village the characters have reached stop all work every 77 days for a festival. Why? It celebrates an ascended local hero who saved the village from a magical blight. Why 77 days? It took 77 days for effort for the blight to be defeated. ... And so on.

This is a rapid way to both build depth in your setting quickly, as well as inspire possible mysteries and intrigue for investigation later.

A slight modification works also for giving NPCs depth.

Read George Polti's The 36 Dramatic Situations. It's a list of plot elements that have a snappy title, a list of participants in the plot element, a brief discussion of how it works, and then (unfortunately dated) references to dramas that used them.

Using this when building a world, or a campaign, or a local setting, lets you quickly set up a bunch of conflicts (ideally with interlaced participants so that single NPCs (or PCs) can be in different roles in different dramatic situations. Then you just let the events flow logically, and as the dramatic situations get resolved you get a plot. PCs can interfere with these dramatic situations and thus have an impact on resulting plots even if the overall setting is far larger than they are.

What's... What's GM camaro?

Also make maps that people in universe would use, not a god or modern satellite images. Romans used maps that showed main roads and villages, why would a random adventurer need a super detailed map with borders on it.

Well.... That doesn't always go the way you'd want it to go.

As this "short" session shows.

FWIW, I have never managed to achieve that fluently. To elegantly switch from "sitting around, planning" to interacting with the world. Retrospections are the only way that works for me