For best outputs and usage:

Sampler: DPM++ 2M Karras (faster, slightly less overall quality) / DPM++ 3M SDE Karras (slower, better overall quality). Other accepted samplers are Euler a, Restart, DPM++ 2M SDE Karras, DPM++ 3M SDE, DPM++ 2M, DPM++ SDE. Overall, the SDE family will output better quality, but its slower as back.

Steps: 30 ~ 70, cfg 3 (for realism and skin detailing) ~ 7 (for artstic, anime, surrealism, and so on), CLIP skip 3.

VAE: none required.

Pos prompt: this model is by default set to semi-realism. Can be pushed to almost photorealism with the proper keywords in both pos and neg prompts, as well as into anime or other realism levels. Knows several art forms and it's aware of the pop culture. It's not bad at text either. Quality keywords like "best quality, Masterpiece" may help to improve overall quality too.

Neg prompt: can be left blank / what you don't want to see. It can also be used to guide the model towards the level of realism you desire.

The model stands 768 x 1024 / 1024 x 768, but best outputs at 1024 x 1024.

Checkpoint Trained.