How to Write Sarcasm

Ignore what they say—sarcasm isn’t the lowest form of wit. It may also not be the highest form of intelligent (sorry). But it is fun. It doesn’t always translate well into writing, though.

In the digital age emojis can make it easier to get your point across, but how do you write sarcasm that comes across as sarcasm and not you being an arse without using emojis?