Saulkar said:
That would be all fine and dandy if there were actual instructions on how to. The fact of the matter is words hurt. There is nothing that can really change that. Not everybody is born with a thick skin that can shake off words. Words have no physical nature but they have real connotations that the brain recognises, this in turn translates into feelings or understanding and thus negative words can still hurt for this reason...
Long post following.
I think a lot of what has been said so far in response to this discussion has been what you might call "Solipsistic". You draw a line in the sand between "me" and "other people", and then set about systematically removing yourself from engaging in certain types of discussion by not putting yourself on the line, setting yourself up in such a way that crossing the line is something you develop coping mechanisms for (humour/self-confidence/self-deprecation/distance), or drawing the line in such a way that nothing is ever personal.
I don't think this is the right way to go about resolving the problem of being offended, for the simple reason that you don't really address what it was about what they said that gave rise to the perceived offense. Someone else has said something that would have offended you; this was said in the way it was for a reason, and dismissing that reason can in certain situations result in a misinterpretation of the other person's intent in saying it. Joking around it or shrugging it off are deflection methods, whereas being offensive towards you sometimes has a very important part to play in explaining perceived problems with the way you have conducted yourself.
Resolving occasions of offense isn't about building your own sense of self-esteem and set of personal defenses up. It's about reading the situation from the lens of the intention the other person has in causing it.
Often, this reading is easy. Someone might have said something just because they're starved for attention, and offense is a very good way to attract it. Then there's no reason to think that what is said has anything to do with you whatsoever. Sometimes it's a strategy they adopt in order to distract you from the game they perceive to be in effect - in which case, again, it's just because you're their opponent. Someone might have said something because they're frustrated that you don't agree with their opinion, even if you've given a reasonable explanation of why you believe what you do - in which case, explaining your perspective and calmly asking them to acknowledge the difference is often good enough. Usually online, these readings tend to work because of the typically fleeting nature of conversation.
It's occasionally a little trickier, and that's where interpersonal empathy is a very useful tool. Try to view what had happened up to that point from a different perspective, and see if you can think about how has the occasion of offense-giving emerged from the context. If you can't work it out, then ask them!
Everyone acts for a reason. People can act "irrationally" and act in ways that don't always make sense from the impartial viewpoint, but they have their own internal logic that drives their decisions (albeit one usually mired in contradiction). If you accept this as a premise, and consider the resultant important role that interpretation plays in the function of words and language, then maybe you can use sensitivity to offense as an opportunity to engage deeper in the intentions and thoughts of the other people involved in the discussion.
It's not so much about self-confidence as it is about Strength of Will. You can be happy to change things about yourself and respond positively to emotive criticism wthout backing down from authority and ownership of your position in the conversation.
tl;dr - escaping from offense isn't always the most constructive approach to dealing with people.