Starting at around a 0.75 weight is good for most cases. Moving it up or down will cause interesting changes. This plays especially nice with known sci-fi type themes. This model will have trouble with scenes that are already calling for a lot of heavy detail - use it with simple prompts to get extra details without complicating the prompt. For closer shots, leaving "restore faces" turned off can bring some really nice face details. I love the big, clear eyes this makes, too. https://civitai.com/models/89693/xeno-detailer-magic-scene-detailer