These tips will be useful for everyone:

-Just because you can turn up the bass on your stereo loud enough to drown out all other frequencies doesn't mean you should.
-If you don't know how to use EQ, just leave it flat. It sounds better than the ass you are probably going to dial up.
-If being in the same room as your stereo causes my ears to ring, use your brain for once and turn it down.

These tips will be useful for professional types:

-In the studio, don't record a brick off sound. Making everything as loud as possible sounds like pure ass.
-For the man behind the sound board at a concert, most people would like to be able to hear each instrument. Please help make this a possibility.
-Don't deafen me if I am at your show. Please!
-If you are DJ-ing someplace I am at, please turn your shitty music down low enough to at least allow me to have a conversation.

All of these "tips" are related to recent experiences I've had with people trying to piss me off by not knowing how to play music correctly. Well, the live music complaints are kind of old but so few engineers know what they are doing in live settings its not even funny.