At the age of about 18 I got the best advice I've ever had regarding projection of my voice. It came from Ted Edwards a long time friend who worked the folk clubs of the North West(England)

It went thus "pick out t'best looking bird on t'back row and sing to 'er, if she can hear yu everyone else can"

Over a very short period of time my projection grew immensely and I've never forgotten those pearls of wisdom