Here's a video from IABC Calgary, in which Katie Paine provides some measurement tips. (It takes a minute to get to Ms. Paine's advice, and, yes, that background music is a bit much.) --WTP
“Do not believe in anything simply because you have heard it. Do not believe in anything simply because it is spoken and rumored by many… Do not believe in anything merely on the authority of your teachers and elders... But after observation and analysis, when you find that anything agrees with reason and is conducive to the good and benefit of one and all, then accept it and live up to it.”