The most commonly known emote. Simply press the crouch key, defaulted to 'CTRL', repeatedly.
You can do this while loading in, making it an excellent emote pick.

While you cannot use your gun during the pre-game lobby, some have discovered you are able to perform melee attacks. You can even perform heavy melee attacks by holding the melee button down!

Punching is an excellent addition to the emote roster.

One of the more 'fresh' emotes to emerge onto the scene. You can press the parry button, defaulted to 'F', and your character while crouch down, light up blue, and make a nice funny sound effect.

You can only use this emote every few seconds, making it a great emote to combo off of, but not very powerful when used on its own.

One of the most rare of emotes, as many have not discovered it yet. However, it has been discovered that when you open the shop screen, your character will open a gold ethereal book.

This emote is best used in quick succession, which while creating a book fluttering effect before your character. It is quite strong on its own, and can easily be paired with other emotes to form various combos.

Somewhat of a low tier emote, and restricted to certain characters. But some characters have animations when using their ADS, such as Bebop.

A newly discovered emote reveals that each character has a joint at their hips. This means you should be able to keep your legs rotated in one direction, while slowly rotating your aim around.

This can lead to all sort of fun contortions with your character, such as point your but at them, while your upper body is twisted around facing them. Fun indeed.

User Zombie Jesus has reported the following:

Originally posted by Zombie Jesus:

Mirage will fist pump if you point his gun straight up into the air and spam the aim key