Today's Tip: Find a map to the high road and stick to it. Anyone who has followed me has probably seen that I don't do many cheap shots at people in my comments section, and trust me it is very difficult at times. The average flamer (someone who hurls insults in blog comments) most of the time are borderline illiterate, if you haven't noticed. Most of them also didn't actually read what you wrote or worse yet didn't actually comprehend it, jumped to a conclusion, and then hurled insults. Trust me, it happens a lot, and if it doesn't happen to you, it will sooner or later.
Now you need to think of your online presence the same way you think about your offline presence. When a drunken fool approaches you and slurs their words, while getting aggressive with you, do you take the time to pick on their improper use of English? Yeah I don't either, because they get worse, and chances are pretty good that regardless of how big or clever I am, they won't feel the pain they can and I will. That's real life 101, not just blogging 101. Being a grammar Nazi or hurling insults back simply makes that person hate you more, and whether they deserve to or not, the last thing you want is someone energized to drag you down to their level. At that point they might have already.
I find in most cases condescension works best. Simply apologize for something (anything) and hope they go away. They usually do. There are some that you can tell have been ramping up to progressively get worse, and the best thing to do as I have said in other tips, is to ignore them completely. Let them say what they want, and leave it there for others to see without acknowledging it. If they realize they were out of bounds, ignorant or just plain mean for whatever reason, they will usually come back and delete it. If they don't then again you have a signal buoy out there for others.