It turns out that emoticons are considered a symbol, so they can beef up your passwords and make them more secure in combination with letters and numbers. Here’s how.
It will look like it's random - for example "I like my lemmy only with beans and bacon" becomes "ilmlowbab" - and it comes from a far vaster possibility space (ever possible sentence and it need not even make sense) than that of "words in the English language and derived words" so it's a lot harder to try to crack with a dictionary attack.
Also it works in everything that takes ASCII charactes (i.e. everything but numeric only pin codes).