Recommended settings:

1. Sampler: Euler A
2. Scheduler: AYS/SGM Uniform
3. CFG: 6
4. Steps: 20-30 (You can go as low as 15)
5. Positive prompt: masterpiece, best quality

Recommended negative prompt: lowres, bad quality, worst quality, bad anatomy, jpeg artifacts, signature, watermark, sketch

I also recommend using this upscaler: https://openmodeldb.info/models/2x-AnimeSharpV4