For Illustrious: images made with NoobAI, using cartoon tag can help.

Trained on art by Inusen mainly the Milftoon and visual novel game.

Highres fix or Raw. Mainly tried on regular pony and autism mix

Using tag "Flat colors" will help a lot.

ADetailer for faces and hands will help.

Couldn't get it to work for 1.5 so far but I'll keep trying.