I don't get irritated by the trivial things other people do, but I'm bothered by my own sloppy speech.

I say "gonna"
hafta
wanna
s'posed'ta
coulda

I contract "I will not" to something like "um'not" and instead of just contracting "we are ready" to "we're ready" I will also contract "boxes're ready" "wheels're ready" and so on.

I say "goin'"
lookin'

I run words together like "can we" as "canwee"

I use the word "got" instead of some form of to have.

I'm sure there are many other habits of speech that I would change if I were more mindful of them.