Paring with Ping Pong TDD works really well. Improves paring with frequent driver/navigator switches and improves TDD by having the navigator thinking ahead. Been doing it almost exclusively for 14 years.

Hiring for pairing is important. It's not for everyone, although not everyone has been in an environment where it's done well. I make sure to let people know they will be pairing full time on my teams and ask if they are comfortable with that. Also won't hire anyone that would be significantly slow to work with (can't touch type, slow thought process)