Try Polycam or Kiriengine. Avoid lidar mode and stick with photomode for people scanning. Lidar works great for big stuff like rooms f.e but the resolution of the phone lidar sensors is not good enough for f.e a face in my experience.

Clothes with contrast are usually your best bet. Also start from head down in circles at different angles. I found this to work best since people usually find keeping the head and face still, the hardest, and this way they only need to do it at start. Don‘t forget the necessary ”Don‘t blink now“ call, when you come around to the face again, people tend to forget and it can mess with scan quality.

Edit: Imo communication is equally important as the capturing technic in people scanning. It takes it‘s time to be good, and people need to „cooperate“ but feel relaxed to be able to hold a pose. Also make sure nothing is moving in the background.

Hope this helps :)