Giving Taija a specific place to be as guests approach the house helps me a lot. I think it just gives her a better understanding of her boundaries.
Mentally stimulating games and new tricks helps to keep her digging to a minimum.

With a dog like a Border Collie, I know they have strong herding instincts. Could that be something worth looking into??

Other than that with Taija literally doing nothing has helped with her over excitedness the most. Or 'being a tree'

Definitely second the NILIF idea - I swear by it.