Question: what are cool ways to say hello?
Answer: WHAT'S THE CRAIC? How they say “What's up?” in Ireland. ... 
HOW HOPS IT? Be classically cool with this late 19th-century slang for “How's it going?”
AHOY. Add a little jaunty excitement by getting into pirate mode.
[HAT TIP] ... 
THERE HE/SHE IS! ... 
CIAO. ... 
S.P.D.S.V.B.E.E.V. ... 
SALUTATIONS.