macOS shortcuts

option + p - Pi π

option +f - ƒ

option + z : Ω Omega

option + divison :√

option + b - Integration ∫

option + m -mu µ

Similarly for other letter with option key

  

Frequently used

fn+ delete key - delete one character on right side of cursor

option + 3 - For # (hash)

(Command key, ⌘, formerly also known as the Apple key)

Command + M - Minimise Window

Camtasia 

Shift + Command + 2 - Start recording