Some quick tips for peeps using MJ that don't want it to look like everyone else using MJ.
1. The Ultra Stylish All Dress Alike
First, adjust your style setting (--s (number)). This is how much of the Midjourney 'secret sauce' is added. The lower this number, the closer to your prompt the style will be, at a cost of coherence and 'prettiness'.
Same prompt, same seed, style 500 on the left, style 25 (my preferred setting) on the right. The differences in lighting, pose, skin reflectivity, etc are apparent. You can think of it as a "de-instagram" setting.
3. Use your Variations
"A dinosaur astronaut", original gen, vary (subtle) and Vary (strong) results
If you get something you like for an initial result, the first thing I tend to do is immediately to a Vary (Strong) on it. The results are usually better than the original one because you're essentially re-running the initial prompt with the first result as an additional image prompt, reinforcing the subject.
Using subtle variations to get closer to what you want is one of the big features of MJ, and it's sorely underused.
I recommend setting to low variation mode so your normal variations are subtle ones, and putting on remix mode. Remix mode prompts you to change the prompt every time you do a variation. If you're close but something's not right, that's an easy way to go.
Changing prompts is especially useful if combined with Vary (Region). Basically, if you like everything about a pic but some select details, you can highlight an area and have the system produce new variations just changing that region. It's obvious use is fixing generation errors, but by changing the prompt, you can get results that the robot can't imagine as a solo prompt.
3. Get Weird With It
--weird is a highly unused setting. It's also very powerful, while it goes up to 1000, I tend to not go above 1-5.
A cartoon penguin made of knives at 0 weird, 1 weird, and 50 weird:
Near as I can tell, weird restricts the 'does this make sense' checks, allowing for more out-there results, both in terms of style and subject matter. At the very low levels (1-5) it increases prompt adherence, at higher levels it reduces it substantially.
4. Prompt Big and Blend your Concepts
MJ deals with short prompts by filling in its own leanings where there's gaps, so short prompts look the most midjourney-esq while longer ones (especially when combined with --weird or a low --s value) fight back against it more.
When prompting for art styles, prompting for multiple art styles/artists at once produces weird hybrids. Prompting an artist with the wrong medium (A painting by a sculptor, a drawing by a cinematographer, etc) also can produce new, strange results.
(Lisa Frank/H.R. Giger style mashup using :: technique (below))
But the real trick is in "prompt smashing" or multi-prompting. Basically, midjourney uses :: to split prompts. Intended function is to allow you to add individual weights to each section, if you want something strongly emphasized.
But in practice, it blends the concepts of the two prompts to create a new, third thing.
As above with "an illustration of an armored dinosaur in the woods, in the style of vibrant comics, toycore, ps1 graphics, national geographic photo, majestic elephants, exotic, action painter" then "daft punk & particle party daft punk world tour, in the style of romina ressia, polished craftsmanship, minimalistic metal sculptures, ultra hd, mark seliger, installation-based, quadratura" and then the two prompts run together separated by ::.
Each one was also iterated to produce a better result than the initial gen.
5. Just edit the darn thing.
Learning to edit your works outside of the AI system will always improve your work beyond what the machine itself can do. Whether it's just the simple matter of doing color adjustment/correction:
Or more heavy compositing and re-editing combined with other techniques:
Editing and compositing your gens is always superior to just posting them raw, even if its just a little cropping to get the figure slightly off-center or compiling 20ish individual gens into a single comic-style battle scene before recoloring it from scratch.
But at the very least, before you post, go over the image and make sure there's nothing glaring.