1)The back test
The man runs his finger down the back of said persons back from the bottom of their neck to the where the trousers start. If he feels a bra strap then it is a woman, if not then it is a man.
2)The front test
The man places his hand firmly on said persons upper chest, if it is a man then the subject will be confused, if it is a woman then the tester will be hit quite hard and be called a pervert. This test is only recommended in extreme situations