I use a touchpad so I can't really say anything about mice positions etc but some tips I have is to play creative for both lego fortnite and Battle Royale. You could also change your keybinds and lower your sensitivity when learning KBM. You could also enable edit on release for battle royale building. Try using your dominant hand for the mouse maybe. I don't really have many tips to be honest. Just practice.

@@sggsquadpresents ok thank you