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
Usable weight: from 0 to 2+, depending on the checkpoint and additional LORA used
No trigger word is needed
WARNING: it is quite strong so high weight (>1) ccan change overall composition by a lot
(not a case for v2)