I'm a staunch member of the "a given piece of content should take less time to prep than it does to run" but that can take a while to get into. It's mandatory for sanity though. I know the critical role guy says the opposite but DMing is his job so his situation is entirely different.
Yeah, or at the very least if you're taking the time to prep it have it be something you would enjoy regardless of the outcome. It can't be helped that sometimes you come up with some gordian knot mystery and the players find some way to cut straight through it
I'm kind of variable on giving players freedom. On one hand yes you have to that's what D&D is, but I think there's an unwritten social contract here and one end of it is not making the DM's job impossible. I will occasionally tell my players "okay I don't have anything prepped for that avenue so put a pin in it for the moment and we can come back to that later."
I just see it as running one of three types of games
-Quest, go do a thing. Fairly easy to keep on the rails organically
-Narrative, players jump through a sequence of connected events. Middling ease
-Open world, players set their own goals. No rails
So I ask my players ahead of time what kind of game they want (and make sure to establish what
they mean because I've had tremendously painful experiences with every player asking for open world when they wanted a quest).
Though that can also be a problem. I've played with a lot of people who, for various reasons, take the DM's presentation of the world as a coded message on what they're supposed to do. And will never do things out of the ordinary. Or will even openly discuss my description of the situation like they're trying to figure out what I want them to do. Or even ask me! Very few things get me as salty/discouraged as a player just openly saying "so we're supposed to do X right?" Last game I actually explicitly forbid my players from asking me that and wouldn't even reply.
1 trillion percent in agreement. I've had two players do this and both were used to DMing 5e on their own tables where they had solutions players were supposed to find, things players were supposed to do, and were not accustomed to RPing as a character - more like moving pieces
It's not against the rules to say "don't do that yet please" if they ask to do something completely outside what you're prepared to run.
Hahaha I once asked my players "I don't mind if you exterminatus the entire planet but in character and out of character, have a great reason to do it before you do it. Otherwise all of my notes go up in nuclear fire without anyone seeing it."
As far as designing what you are prepared to run goes I like to design a sort of toolbox rather than a story. Defining all the characters, their goals and resources for achieving those goals, the important locations, etc. And a rough timeline of what will happen if the players never get involved (which should always be one of the worst possible outcomes, because otherwise there's no need for heroic intervention). Then it's like...
1. Trigger inciting event/situation that hooks the players.
2. Players respond to the inciting event and then go about interacting with your situation.
3. Consider how this affects your timeline, how the major NPCs' goals are advanced/hindered
4. Decide their response to this. Do they seek the PCs' help? Do they try to manipulate them, or try to neutralize them?
5. If the NPCs' have new goals, figure out how they go about achieving them using the resources they have
6. Adjust your timeline accordingly (I did say rough right? Keep the timeline rough because every player action will alter it)
I always recommend this. Adventure writing is a complicated balance between giving the players freedom to chart their own path while at the same time not driving yourself insane or making the game aimless. Those articles all give a lot of good advice on balancing it properly.
This is all how I do it, with two additions. 1. Interesting choices, 2. Interesting fights.
Interesting choices make up the most time-sink of the non-numbers crunch prepwork for me. But whenever players are exploring, if there are no interesting choices to make I just describe the exploration to them. If there is an interesting choice to be made (e.g. take the short, quick and dangerous route, or the long and time consuming but safe route) then I work on adding the atmospheric description stuff and populating their choices with obvious obstacles & rewards. Meeting new people, I think what interesting choices can I add here. What can these people do for my players, both positive and hostile.
The interesting fights is really just a continuation of this design philosophy. So traps aren't hidden, but shown. Many of them are not even things players would recognise as traps. E.g. a shallow pool with a hungry gator sitting by it. A cauldron full of acid or a rotten floorboard that looks like it's going to collapse. Players have great fun trying to bypass or take advantage of these kinds of things, so the more information and meaningful choices they get the better. I also use Dwarf Fortress personality traits and combat lethality as a rough brush to get an idea for more important NPCs (I use a table that auto-rolls their traits) whilst for the generic NPC templates I just scribble down the important stuff like "these dock workers are fiercely loyal to their foreman" or "the office workers are despondent and visibly exhausted."
For the combat notes I put what kind of combat actions they're likely to take. A kill-team squad is going to behave very differently from a mob of zombies, a panicked mob of servants, a chaos champion or an elite bounty hunter team. E.g:
-Kill team squad is fiercely loyal and well-organised. They are very resourceful and very tolerant of casualties, but will not leave injured soldiers behind. When they encountered my players, their vanguard breached the room with armoured shields, smoke grenades and las carbines. Behind them were elite riflemen armed with hellguns, bringing with them an anti-aircraft servitor equipped with hydra flak cannons. The men with the las carbines and the flak would keep suppressive fire on enemy targets while the men with the hell guns would take careful aim and place kill shots. Whilst the riflemen placed kill shots, the men with the las carbines would push the battle line forward, throwing grenades at anyone in cover. Their objective, which they prioritised above all else, was to extract the noble patriarch - the same target the players were trying to eliminate.
-The mob of zombies is fearless but hollow. The most intelligent plan it is still capable of is pretending to be dead, picking up a rock or a pipe as a weapon, or pleading for help. Their objective is to shamble towards whoever is healthy and make more zombies. If they don't see anyone healthy they just imitate what they did when they were still sane to the best of their ability, going through the motions of cooking/working/conversing e.t.c.
Despite being weak, will always try to finish off any players who are injured or downed first, so players don't treat them light heartedly! I also used DF logic on undead... Which is to say that removing the head usually killed the zombie, but not always. That came as quite a shock ;]
-The panicked mob of servants I just use to stat any servant NPC they encounter in the palace. If one of these poor lads or ladies ends up in combat, they do their best to dodge fire, run away from anyone melee and if possible, hide. If all else fails they will throw a vase at the offending attacker, and then try running away. If they have a gun, they will keep it for moral support, however they will not use it on a living person except as an absolute last resort [zombies count. Most of the zombies were people they knew].
-The chaos champion will attack the players if they're visibly armoured and armed. He'll alternate between all out attacks, swift jabs and will prefer to block their hits than dodge. He'll never escalate violence, and if players grapple him he'll contest to try and reverse the grapple. If players pass out from fatigue or surrender he stops the fight. Throughout the fight he'll talk about how much he loves his wif with all his lif, or how great the sun shining is, all whilst drop kicking them, charging into them, throwing them into walls. If he defeats them, he thanks them for a good fight and leaves. If they fight dishonourably, he draws his sword and starts fighting no holds quarter. If they fight honourably, defeat him, he requests to be slain. If they still spare him, he feels terribly ashamed and gives them a summoning stone if they ever need help dying gloriously in battle.
-The bounty hunter team will attempt to capture the players, kill anyone around them and get out. If they can't capture the players, will kill them. If the fight goes badly for them or lasts too long, will attempt a fighting retreat. Half-ogryn gunner will do the suppressive fire to keep them pinned and stop them flying around. The sniper will attempt to shoot out their power-armour from behind to disable their power packs, making capturing them easy. The scout will attempt to ambush them from concealment, hitting them with a haywire grenade to disable their power armour/weapons and then unload with his combat shotgun. Their boss will run in close with his webber pistol and needlegun if taking them alive is possible, otherwise he'll use his plasma pistol and bolt pistol. If they're able to capture even one of the players their comms guy will attempt to call for extraction. Comms guy will avoid combat at all costs. Boss man will not endanger his men if it's futile. His men will flee or surrender if the boss is killed.
All these little details give more flavour and colour to the world, in a way that also gives players more tactical choices and considerations. E.g. a large predatory bird is NOT okay to leave around downed players, as they will grab them and drag them back to its nest to feed to its young. Conversely, leaving downed players around an enemy black knight is fine, because for all their evil, they are a knight and have promised to look after their source of ransom.