A lot of times, I base my OTPs upon how much I really think they should be making out like, RIGHT NOW, without any delay. If they do make out without any delay, then all is alright with the world and I can sit back and be ridiculously happy about it.
But on the occasions that this is not the case, then I must conduct in my head exactly WHY makeouts are not happening right this very moment, in order to deal with this frustration.
CASES IN POINT BEING MANY
For example, Riza Hawkeye and Roy Mustang, who have needed to make out ever since she dumped him on his ass to deal with Scar. In my mind they have already probably kissed or had sex or SOMETHING, but clearly also have a working relationship, and must have some sort of understanding about not being together until things get done (either the workday or Roy becoming Fuhrer or something like that.) With Ed and Winry it's clearly just teenage stubbornness or something like that, and they will get over that.
Or in the case of Dairine and Roshaun, while they ostensibly hated each other, I did not care, but for the entirety of Wizards at War I just wondered "WHY ARE YOU NOT SMOOSHING YOUR FACES TOGETHER RIGHT ABOUT NOW??!!" And the best reasons I could come up with were Dairine's being eleven-ish (though uhh, my brain smooths over that part, hahaha) and Roshaun's social obligations to being king of his own planet. And I am thoroughly convinced that if various things had not happened in the course of the ending of that book, there would have been lots and lots of kissing, the end.
Nita and Kit are one of those situations where they eventually DO realize their ridiculous OTP-ness, and I was satisfied with the fact that they did not want to ruin their friendship by acknowledging this. But from like the third book on I was rolling my eyes and saying, "omg, just kiss already, geez". (And even though they are, infact, canon otp now, I am still wondering about this. NO SERIOUSLY, AWOM, WHERE WAS THE KISSING??!!)
Watching Firefly, one of the things that I wanted the most out of Serenity was for Simon and Kaylee to finally make out. (And they delivered, thank you). Shinichi and Ran I ship because they just like, give these longing looks at each other and then are continuously cockblocked by plot. For another FMA example, Al/Mei kind of depresses me because he is, thus far, quite bodiless and even if I love them together a lot, they cannot kiss or anything. (They cannot even touch.)
So for me, I think that kissing is kind of this important thing about OTPs for me. Which is weird, because I know, intellectually, that physical intimacy is not what makes a relationship. But I find it a lot harder to get behind an OTP when I don't care if they kiss or not. (Which is not to say that I can't get behind them as BFFs, because I do that a lot.)
And I guess I can trace that back to my own relationships, considering it takes me a lot to be comfortable with physical intimacy (whether it is hugs or kissing or whatever) with people whom I am involved with romantically, so for me kissing is kind of a big deal and a hallmark of people who are quite close to each other. It kind of makes me wonder what other things from my own life (romantic or otherwise) I am projecting onto shows that I like.
Something to ponder.
So what about you, flist? What do you look for in an OTP? (Do you even OTP?)