How do you make a person faint?

Aside from injuring them in some way, you can't. There are a rare few people that faint from the sight of blood/fear etc. but the majority of fainting is due to a physiological response as the result of illness or injury. The stereotypical women fainting because they were emotional historically was due to the corsets that they were wearing limiting their oxygen intake and they were most likely under nourished as well.