The biggest thing is to remember that they can't read your mind, so speak up. There's a big difference between, "I'm working 80 hours a week so I can make lots of money" and "I'm working 80 hours a week so I can help with my sick relatives nursing home bill" or "I'm working 80 hours a week because I'm self concious about my teeth and want to get them fixed." - they can tolerate it more when they understand. If you don't give them enough detail, their imagination will fill in the blanks with things like "they don't care about me" and "they don't want to make time for me." that's when the relationship falls apart.
I've been terrible at that in the past. Any tips?