The Fantasy Trip was a role-playing game that came out in 1980 with the release of In The Labyrinth, the core rule set. It also included Melee (tactical combat) and Wizard (spellcasting), as well as the Advanced versions of them. The game was written by Steve Jackson who later used the system as a base for GURPS. This series of articles is a look at the rules of The Fantasy Trip as seen through modern eyes.
Chapter III of In the Labyrinth covers Creating A World and starts immediately with the dungeon (or labyrinth). In part of the section on Stocking The Labyrinth, they mention writing up some index cards with stats on them for some of the monsters the characters will encounter. This is not a radical idea as I've seen it mentioned in various places over the years. However, they take it up a notch and in a slightly different direction.
TFT suggests using such index cards to add a random element to what could be rather ordinary "crunchy" encounters. Prepare a number of cards with a different monster on each card. If the labyrinth is full of goblins, make a bunch of relatively equal in power goblins and give each of them a separate card. You can then mark your map with something like 4 goblins, 10 goblins, 2 goblins. Then you simply pull out that number of cards from your pile when the characters get there.
This will make sure the monsters feel organic as opposed to a set encounter done for the sake of ease. To me, it can be jarring when all of the monsters in the room are wearing the exact same armor type and using the exact same weapons. This makes it so the characters are fighting the goblin with the spear, instead of goblin #3.
While it will take a bit more prep time, I like the idea.