For the best outputs:

Sampler: DPM++ 3M SDE Karras / DPM++ 2M SDE Heun Karras.

Steps: 60, cfg 7, CLIP skip 2.

VAE: none required.

Pos prompt: quality keywords actually do improve the output. For example, wrap your text between "realistic proportion), (1 girl), (wild pose), ((masterpiece)), (8k wallpaper), HDR, ((extremely detailed face)), amazing cinematic" and "((best quality)), illustration, (fluttered hair), (extremely detailed background), lens flare".

Neg prompt: "bad structures, bad clothes, watermark, bad ratio, bad toe, bad finger, bad foot, clone, big breasts, giant, long neck, extra finger, mutated finger, duplicate, bad hands, wrong limb, extra limb, low res, bad anatomy, bad hands, text, error, missing fingers, extra digit, fewer digits, cropped, worst quality, low quality, normal quality, jpeg artifacts, signature, watermark, username, blurry, penis, extra hand, bad toes, bad fingers, ugly, (incorrect hands), (incorrect fingers)".