I am having this problem with my pup. She is particularly more excited when we are laying down and she has access to our head and ears lol. What I do clap really loud and say NO! That kind of catches her off guard and if she doesn't settle down then I put her in the bathroom and let her have a little time out. You could also divert her mouth to other things. When she starts biting or nipping me I stick a toy in her mouth and hold it there so she can't move her head away to bite me.
Ignoring her when she is doing something that is unwanted should help as its no fun to not have your attention on them.
