Redommendations:

Use Illustrious-XL for the base model, for what I've tested so far, that one is the one that gives the best outputs

Add to the prompt:

simple background, outline, white outline, black outline

To make it look better

Also add to negative prompt

chest fur

since the lora tends to add chest fur, probably it has to do with "white fur" tag, so that one can be deleted to fix it too.