Most, but not all, BAMF Switches result in some kind of fight scene.
BAMF Switches are often characterized by:
1.) Changes in music. (Raised tempo, a more intense genre, or even no music at all.)
2.) Monologing, or, more commonly, a single phrase.
4.) Slow Motion
5.) Reloading a weapon
6.) A physical gesture, such as cracking the neck or knuckles, or awesomely punching someone.
7.) Shifting Gears (If in a vehicle)
8.) A Close up. Especially if the character has just done something very dramatic, such as falling in a pool of blood, or cutting some dude in half.
9.) A change in Weather. Often to high winds or rain. (Similar effects can be given by sprinklers, or large fans)
10.) A Physical Transformation. (Putting on armor or some kind of awesome suit, changing into some kind of creature, or transforming from a vehicle into a giant robot.)
The Rundown: The Rock, while holding the two shotguns in the village raid scene.
300: Like, every five seconds.
Friend 1: Aww! Here comes the BAMF Switch!
Friend 2: Nice!