As told in the time-honored tradition of the Listicle format, with GIFs. Although you may not take this seriously, as a citizen of the Internet I like keeping tabs on these weird meta things.
CAPS LOCK
Easiest and most blunt, the virtual equivalent of shouting.

StIcKy CaPs
(A) Attempt to cutesify all caps. Combined with text speak, this has also devolved into Jejespeak. (B) Also recently combined with a Spongebob image to convey a mocking tone.

*Asterisks*
Convention to indicate boldface.
_Underscores_
Convention to indicate italics or underlines.

Disclaimer: Markdown syntax is slightly different.
/Slashes/
Another way to indicate italic.

“Quotation marks”
For those who misunderstood what quotes are supposed to do.

~Tildes~
(A) to provide estimates; (B) to denote something fancy or sarcastic; or (C) to draw things out in a sing-song voice. More research from Buzzfeed & /r/outoftheloop.

~*~Asterisks with tildes~*~
Fancy and sparkly.

#Hashtags
To hint at what you’re humblebragging about, or for when you’ve run out of characters for your tweet.

Capitalized Words
To carry the same air of importance that Proper Nouns have.

P.e.r.i.o.d.s.
To carry the same air of importance that acronyms have.

H-Y-P-H-E-N-S
To spell it out for you very slowly.

S P A C E D O U T L E T T E R S
To emulate the Vaporwave A E S T H E T I C (ironically or not). Or to practice some nice whitespaced tracking.

Words. Separated. By. Periods.
To enunciate or speak in stunted sentences.
Exclamation!points!
(A) to indicate excitement; or (B) to make the first word a modifier of the second word.

Question?Marks?
When you’re just not sure.

Repeeeeaatiiinnngggg Lettteeeerrrssss
To visually show how long it takes to enunciate.

Exaggerated exclamation points!!!!!1111one
Hyperbolic excitement. So thrilled to type that you forget to hit the shift key and get 1’s instead.

Deleted Text
For FTFY (fixed that for you) replies and other things that need to be corrected or revised.

NestedSuperscriptText
To trail off statements, predominantly used on Reddit.

👏Ratchet👏Clap👏
To replace spaces with the clapping emoji when you need to declare something major. Can also use similar emoji like 📢 or 🗣.

ASCII Formation
To make an image out of good ol’ text.
