You try and nurture the relationship. This day and age we have to do a little more networking than we used to do. All that does is make sure you befriend the people you are working with on a project so you hopefully carry it over to the next one.
Sometimes I just listen to classical pieces of music to take me away from my work. That's what I kind of do to wash away the notes that I've been working on all day. As human beings we need to sleep so that's kind of one of my little tricks.