--Do not go out of your way to make a pun, and then follow it up with "No pun intended."
You've created a pun--you even might say you have a pun in the oven*--so own up to it.
--Do not invent tortured acronyms. Also, do not use as the first word of your acronym the word that the acronym spells out. This was in a news story I read recently: "Smart Antenna RF Test Alliance (SMART)."
No, that's not SMART. It's SARFTA. And it's STUPID (Stupid Tortured Unhelpful Piddly Initials are Dumb).
--Don't say "No offense, but" just before you say something that's obviously intended to offend. For example, "No offense, but screw you."
If you do that, well, no offense, but screw you.
Wait ... actually, that one's sort of satisfying. Never mind.