A manly hug between to bros.
A bro hug is executed my first initiating a mid-five/handshake, in which the bros then pull into eachother from hand contact. Then, each bro swings one arm around the back of the other bro, and gives 1-3 open palmed slaps on the opposing bro's shoulder, all while the mid-five/handshake is still interlocked, effectively sandwiching the arms between the bros.
It's hard to mess up a bro hug, but it is often done in one of two ways:
1) Not being rigid or forceful enough.
2) Using both arms to hug (that's gay, bro).
3) Holding it too long (timing is everything, bro).
The Bro Hug must be seen, not heard or read.