1. Get them up so early in the morning that they're just too tired to be nervous.
2. Give your subject something to hold so they're not thinking about what to do with their hands.
3. Many photographers get their subjects a little tipsy before shooting. While I'm not usually an advocate of this approach, if I'm gonna do it I don't mess around...
I might even join in myself...
...but not too much drinking or bad things can happen.
4. If alchohol's not your thing, ice cream is a good alternative. Gets the blood pumping.
5. Encourage your subject to bring a friend or two...
...or a rock star.
6. If you're shooting an engagement photo, go back to the place where it all began.
7. Kids hate to stand still, so don't ask them to.
8. If you're shooting a group photo and they don't know what to do...
...have them try some silly stuff to loosen up. It will probably be the photo they love the most.
9. Encourage them to wear the clothing that suits them best.
10. If you ask your subject to do something dangerous...
...do it with them.
11. Respect their personal space. Get a long lens and shoot from really far away. Especially if you have bad breath.
12. Show some enthusiasm for the photos. It will encourage them to go further.
13. If you're shooting outside and they complain about the cold weather, suffer with them in solidarity.
14. If they keep complaining, challenge them to a push-up contest. That'll warm them up.
15. Finally, tattoo this positive affirmation to your arm and refer to it whenever your subject says "No" to anything!