I'm not sure if it was my continued pressing of her, or if she just happened to come across orgasm denial randomly one day - I like to think my training attempts bore fruit, but hey I'm not that picky. To shorten a long story, I was on board for the orgasm denial, like I needed an excuse to exercise control or something - yeah right. Things went well, really well actually. There is a point where she tips over the top of 'interested' and starts falling into the valley of 'cranky' but once we located that point it is easy to manipulate.
I think it was during that process that she found enjoyment in casual attention. While she was being denied she would beg to just be played with even knowing there wasn't going to be a 'happy ending'. I wasn't one to object, but I still had other things to do, so she got 'unfocused' attention a lot of the time (this feeds into her mild objectification fetish). And this is where we are today.
The mental process -
I like begging, desperation, focused 'neediness' and incoherent 'want'. I like being the one to both give the sensation that leads up to that point, and to control if it continues, stops, or moves into something more intense. If you've been following along this is likely a 'so what else is new' moment since I seem to say that kind of thing a lot. There is something to be said of having a 'toy' to play with while you're doing other things - if you haven't tried it, you don't know what you're missing.
The physical process -
This isn't static of course, but is dependant on the position I'm in. Generally the position involves her leaning against me with my arm around her, or her laying with her head in my lap - this gives me access to the top half of her body. Now I love her breasts, don't get me wrong, but that isn't what it's all about either. Remember this is usually 'passive' attention - I'm not really focusing on what I'm doing. This usually involves petting, stroking and mild nipple play. Often I'll just stroke her hair, or idly slide my fingers across her stomach.
To pick things up a bit I'll take a minute or two and focus on her nipples, or some mild breath play. I usually don't continue for prolonged periods when I'm just teasing - partly because that takes focus, and partly because usually we're watching TV and if I play with her too much she completely misses what's going on (surprise surprise).
I guess in short, it really doesn't matter 'what' you're doing - its the touch that matters. Mix up casual touching with more intimate 'playing' and eventually you get her in a 'state' (as she calls it). Doing this for hours is apparently a form of pleasure torture, since she begins writhing and whimpering.
Now the touch differs if say, she's laying beside me and I'm sitting up. Then I can reach her lower half, and it's even more fun (though more intense) to idly play with her clit than with her nipples. Obviously it's more sensitive, (YMMV here) you really don't have to do much here to get the same effect - long periods of gentle stimulation usually get to the begging stage faster than anything else. There is also a host of sexy things about a woman's legs that I'll leave you to discover on your own if you don't know already.
Without going into orgasm denial (since I think that's a separate topic) I wanted to touch on edging a bit while we were talking about teasing. This is a more direct form of teasing that both takes concentration and a bit of knowledge of your partner. What do I mean by edging?
For me, edging is when I am giving her 'intense' stimulation to the point where she 'could' cum. Now in our dynamic she has to ask, again YMMV, so I have the luxury of saying 'not yet' and having her co-operate here. If you don't have that luxury you just have to be a bit more careful. Changing the stimulation, backing off, or alternately doing something and 'not' allowing her to cum at that point is (I'm sure) torture enough, but the key here is to keep her at that point. Never let the 'pleasure' fade off, keep doing what you're doing to hold her at that point.
This is where the knowledge of your partner is necessary. I can read when she's getting close, so I know if I need to back off a bit. I like knowing how my toys work (inside and out) so this was a fun process for me to discover. Now I feel like I can play her like an instrument, pushing a button here, stroke a chord there and voila!
Also with edging I'd be careful not to 'overdo' it. I think at some point it starts to lose it's effectiveness, you'll have to determine that point for yourself. It's also fatiguing on you (the doer) to keep up that stimulation indefinately. I usually set a realistic time, like 5 or 10 minutes. I also like telling her what the current time limit is going to be and counting it off for her. Sometimes I count backwards and watch her get a really wild/frustrated/angry look in her eyes that makes it all worth it.
To end -
I think the teasing ties more into the mental aspect of submission than into the physical. If you're interested in mental domination it's definitely something that should be in your 'bag of tricks'. There are a multitude of ways you can fuck her head while you're fucking with her body at the same time - I won't give away all my secrets, but if you're even a little sadistic I'm sure you can already see the possibilities.