Recommended settings:

1. Sampler: Euler A

2. Scheduler: Automatic/simple

3. CFG: 6

4. Steps: 20-30 (You can go as low as 15)

5. Positive prompt: leave blank (masterpiece/best quality is optional)

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

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