What are your best TTPs to pass knowledge and continuity?

Leaders, we've all been there, a time to PCS,  a move to another unit, or simply moving up to new positions.  We aren't irreplaceable and someone will be assigned to take over YOUR position and duties.  What have you found to be the best and most effective way to transfer continuity and knowledge along? A post-it note, a left seat/right seat (if possible), a book....? How do you handle the challenge of transitioning your duties without letting your organization lose momentum?