Is it just a simple hi, how are you or what's up with a head nod? Maybe a what's going on or what it is bro?
In today's busy world, to keep your customers you need a distinctive memorable sound, so I always cup my hand to my armpit and squawk a tinny fart sound.
I wish we had a different common greeting in English. The "H" sound force you to expel the air from your lungs, so I find it kind of annoying actually to say "Hi" or "hello". We should go back to something like "goo-day sir".