Hrm... where to start, even...
I very absolutely super-duper DEF-IN-ITE-LY lorv me some teasing, though I've been told that I'm apparently quite good at teasing as well when the mood strikes and when the right dom-side in me stirs.
For being teased... well... I think it has to do with all the attention the partner's putting into just making you squirm without explicitly trying to make you break completely. And well... if you're just being made into a helpless squirmy mess over a period of time... that's a nice, prolonged period of bliss right there. And if they try to draw stuff out of you... make you answer their questions... or even to beg for what you want in excruciating detail... mm... yeah, that's the good stuff... I like being descriptive for my partners. Plus I love being surprised, and if you can just get me flustered and borderline-hyperventilating from it that's absolutely fantastic. Definitely can't ignore that!
In terms of teasing others... that's a side that comes out of me under certain circumstances. I wish I knew more about it but I also feel like a lot of what people like to do with others are also things that they like to experience as well... might not always be the case with every person, mind you, but I feel like it at least applies to myself and a few others, since... when that particular dom-side comes out I've also found myself quite fond of tempting my partners into admitting certain juicy tidbits of information... like a fantasy... an erotic dream they had... how they might... hypothetically... respond to certain actions... they're all delightful. There's also the icing on the cake... getting them to beg for something they want... especially if it's something I was already hungering for too.
Hope this answers your question! I miiiiiiiiiiiiight have neglected the why, maybe, but if I did I may wind up going into more detail another time ^-^