Reduce, Reuse, Recycle for Game Masters

Reduce, Reuse, Recycle is a good baseline for 1970s through 1990s environmentalism campaigns but it works for Game Masters planning RPG sessions.   Admittedly, I spend more time preparing for RPG sessions than I do running said RPG sessions. It is true that I have fun with said planning, but I have fun with a lot of other things I could be doing, so I don't want the effort to be wasted.   I've been applying the three "R"s of environmentalism to make my RPG prep work more efficient and it's helped me, so it might help you.  

Reduce your NPC stat making

  I think the best way to learn a new RPG system is to make some characters, and if you are Game Master, you might as well use the various characters that you make somewhere.   But once you understand an RPG system fairly well, you should pump the breaks on fully statting out hordes of NPCs and save this special treatment for very important NPCs. The players are probably going to never see the stats you made for the NPCs but they are going to remember their interaction with said NPC, so its better to focus on things like story development and characterization.   You only need to stat out the parts of the NPCs you'll need. If the NPCs are not to going to make relevant ability rolls around the PCs at all, you don't even need to give them simplified stats, just names and basic descriptions is usually enough.   NPCs generally have six dice when rolling whatever attribute + ability + specialty pools are directly relevant to their livelihood. Five dice when rolling things closely related to their core livelihood, four dice when rolling things out peripherally rated to their core livelihood and three dice when acting out of their comfort zone.   That's all you need most of the time. NPC dice pools gives examples of how I apply the guidelines above. Guidelines for PCs fighting mooks and How Alert are NPCs? are specific more detailed articles for coming up with fighting stats or providing opposed rolls for PCs who like sneaking around.   Sometimes a random "throwaway NPC" becomes by the players or otherwise evolves into an important ongoing role in the story beyond the Game Master's initial expectations, so at that point, then you can stat out the character in greater detail if and when it becomes necessary.  

Reuse your detailed world building

  Sometimes a Game Master (or gratuitous World Builder) does want to make a detailed character or institution. I like to use reusable generators and templates. Here are some examples.   I made a lot of templates for things that I make over and over again. I created blank Character Stat Templates that I can copy and paste into a word document or World Anvil article and fill out and I have several reference documents to grab descriptions of for things like getting Attribute Descriptions and Ability Descriptions at a glance. These can be handy for players too.   Dwarves, both PCs and NPCs take their clan affiliation seriously and Scarterra has over 150 different dwarf clans, but it would completely unnecessary to write up a description for all of them. But sometimes I want to bring in one or more dwarves and I don't want to use one of the few existing clans I have created profiles. I created the Dwarf Clan Generator to make it quicker and easier to make new dwarf clans.   As my games get more political, it becomes important for me to establish a large supporting cast of lords and ladies. I used the same principles to create my Noble NPC Generator, which is a little more broad and free-form but it uses the same basic principles. The same basic system works for democratically elected leaders and ecclesiastical leaders.   The point is, if you find yourself needing to create the same thing over and over again, I would recommend making a relevant template to streamline the process.    

Recycle Your Plot Elements

  Experienced Game Masters know that no plan survives contact with the Player Characters. Sometimes a GM puts a lot of work into something that becomes unnecessary or unusable.   Hypothetically, lets say you plan an elaborate adventure based around an abandoned castle in the western forest that is now haunted and the PCs never enter the western forest. You can always put the haunted castle somewhere else. Maybe some of the elements of the haunted castle relate to the forest's lore so they need to be rewritten or tweaked but it's easier to change the erring parts rather than to make a new haunted castle from scratch.       Less hypothetically, here's an example from an actual session I ran. I knew the players/PCs set a goal to overthrow an evil despot of a small isolated kingdom. I decided to make the warlord a puppet of a warlock who "serves" him as his right hand enforcer and advisor. The warlock had a backstory and stats and everything. The players came up with a complicated scheme to isolate the warlord and fomented a revolt among the bulk of his soldiers. The warlock sensed the writing on the wall and sneaked away rather than engage the PCs in a battle he had no real hope of winning.   The PCs never even glimpsed the warlock, but with a few minor tweaks, I can throw a socially adept evil warlock somewhere else when a different villain needs an elite henchman.       Another campaign I was running swerved in an unexpected direction where the PCs decided to eliminate four or five sorcery wielding spy masters/mistresses. They had different personalities and different foibles and vices and different spells, but they all had the same core skill set so I only need to come up with their base stats once. Each time the story required a new spy master, I just tweaked the stats of the old one. and reskinned his/her magic spells. A real time saver compared to making five villains from scratch.       This almost goes without saying but I'll state it here, if you don't GM for the same players every time, you can (and probably should) recycle material from old games into new games. Keeping detailed notes makes it easier to reuse and recycle things and World Anvil makes organizing ones detailed notes a fair bit easier.