Midjourney generates images from natural language descriptions, called prompts, similar to OpenAI's DALL-E and Stability AI's Stable Diffusion.

"A prompt is a short text phrase that the Midjourney Bot interprets to produce an image. The Midjourney Bot breaks down the words and phrases in a prompt into smaller pieces, called tokens, that are compared to its training data and then used to generate an image. A well-crafted prompt can help make unique and exciting images." - Source: Midjourney website

Basic Image Prompts

A basic prompt can be as simple, and describes the important elements you would like Midjourney to include.

Advanced Image Prompts

More advanced prompts can include one of more image URLs, text, and various parameters.

Basic parameters

• Aspect ratio: Change the aspect ratio of the image output by using one of the following:
  --aspect or --ar followed by the desired settings e.g. --ar 16:9
• No: negative prompting to remove certain elements from the image. e.g. --no people
• Chaos: Change how varied the results will be; the higher the value the more unusual and unexpected. --chaos <number 0-100> e.g. --chaos 50
• Quality: --q: how much rendering quality time you want spent e.g., --q 2 for high quality
• Stylization: --s: how strongly Midjourney's default aesthetic style is applied; e.g., --s 750 for high stylization.

Check out the Midjourney Prompt Cheat Sheet for more information on parameters and options for prompting.

Prompt:
abandoned hospital at night, with dark, ominous clouds filling the sky above it. The hospital should appear derelict and decaying, with boarded-up windows and walls covered in graffiti. In the foreground, a group of teenagers could be shown breaking into the hospital, with fear and apprehension evident on their faces. The illustration could also include ghostly figures, draped in white sheets, pursuing the teenagers through the darkened hallways of the hospital, conveying a sense of terror and danger. The overall tone of the illustration should be eerie and foreboding, capturing the haunting atmosphere of the story. --ar 16:9

Prompt:
male black model is drowned in thousands doughnuts::2, very slender, mod 70's haircut, wearing oversize fututristic 70's sunglasses, wearing striped and color block slim fit roll neck sweater, with pleated and tapered pant, with chelsea boots, colors of garments should be in neutrals with bright accents, model should be sitting in on a futiristic couch aboard a space ship in the first class lounge. The interior of the lounge should be in colors of pink with camel and gold accents. Very futuristic. r,  High Quality + hyperrealistic + photography + volumetric lightning + octane render + Clear texture + arnold render 3D + Super detailed + Megapixel Cinematic Lightning+ sunlight + same volume and mass of building in attached picture +Anti-Aliasing FXAA, TXAA, RTX, SSAO, Post Processing, Post-Production, Tone Mapping, CGI, VFX, SFX, Full color, Volumetric lightning, HDR, Realistic, 8k --ar 3:2 --s 750

Prompt:
amazing epic chinese ancient theme water & ink style, Fantasy style martial arts style, A woman figure, Meet a killer, rainy day, fight, bamboo forest, lightly detailed, dynamic expressive, clean lines cinematic stunning realistic lighting and shading, vivid, vibrant 8k, octane render, unreal engine very detailed concept art, realistic, Cryengine, --ar 21:9 --q 2 --s 750

For more information visit Midjourney's Quick Start Guide.