For Midjourney users, Permutation Prompts still work in the web interface, as well as the Discord interface.
To do permutations, set to fast mode or add --fast, then put different terms in curly braces { }, with each different term separated by commas.
For example, here's a prompt with two different permutations:
a {happy, sad, remarkable, ordinary} painting from the {Renaissance, Baroque, Rococo, Neoclassicism, Romanticism, Realism, Impressionism, Post-Impressionism, Symbolism, Art Nouveau} period, well-known painter, museum quality
That means, generate with 40 different prompts -- 4 feelings for each of the 10 styles!
You can vary parameters, too, which is a good way to run an experiment with --chaos or --weird, or to vary aspect ratios.
Obviously, be careful with this trick if you don't have lots of GPU time to burn!
Click the link at the top to read the official MJ docs.