Illustrious Recommended settings:

Steps: 30-50+

CFG scale: 4-6

Sampler: dpm ++ 2m sde with karras

positive:

4k photo, (realistic),DSLR,photo, cosplay photo,professional photography,film grain,(masterpiece,best quality,absurdres,highres,very aesthetic:1), 

<YOUR PROMPT>

Negative:

lowres,worst aesthetic,bad quality,worst quality,bad anatomy,jpeg artifacts,scan artifacts,lossy-lossless,unfinished,ugly,poorly drawn,greyscale,
(illustration,2d,3d,painting,cartoons,sketch,anime:1.4),watermark,text, (blurry:1.4)