All these things are such great suggestions Helenearth! I think Soooo much of it has to do with attitude...it plays so much into that "wanton" image Don mentioned!
When I go down on a guy, I don't only concentrate on *him*, I concentrate on the power that position gives ME! Think about how much he wants this, how helpless he is when your lips are wrapped around his cock, how the world revolves around YOU when you are sucking his soul from his body...it's kind of a power trip yes, but it feeds into everything, and makes it a more amazing experience for you both! I can climax while giving oral sex without even touching myself, I love it that much!
But, while we're on the subject...touching yourself while giving him head can be a mighty good show! If he's lying down with a pillow propping his head up, you can kneel at his side so he can see your fingers play as you pleasure him...and the happy noises you make around him will add to his feelings too!
Eye contact is good too. You hear over and over again how much men love being able to look down at a girl on her knees and lock eyes as she takes him into her mouth. I personally love to watch the ecstasy show on his face when I'm making him feel good. It's especially erotic to see the expression on his face as he cums for you! Most guys are verbally excited as well...as you're licking him, tell him how good he tastes, how much you love sucking him, etc. If he is into dirty talk (and you are into talking dirty, hehe!) tell him how much you love being his slutty little cocksucker, how much you want to taste his cum, etc...get as graphic as you are comfortable with!
I definitely chip in for the tease factor! Know his signals for right before he cums...then stop....tease a little...perhaps move away from his cock for a bit, lavish your tongue on his inner thighs, down his legs...suck on his fingers a bit, or go up and taste his lips, nibble at his ears, his neck, etc... Then go back down, bring him to that edge again and again and again. He may seem frustrated at first, but he'll thank you in the end! lol.
And, if you are into being a dirty girl...?! If you aren't too squeamish, pressure to the prostate during a blowjob (or any sexual action, for that matter!) via the rectum seems to be something most fellows enjoy, if they can get past the whole "anal homoerotic" seemingness of it all...
If you or he are not into that intrusive of stimulation, you can get a pretty similar reaction with pressure to the perineal area (between his balls and anus). Seems the best time to do that is when they are close to cumming, especially once they hit that 'point of no return'.
As others have mentioned, it seems that ballplay is a favourite too...licking/sucking/nibbling/scratching with fingernails...up to them (and you) on how hard to do all those of course, but all is fair in sex and war...wait, I got that wrong...ah well
OK, I'll shut up now, I'm gettin' myself all worked up here, hehe!
Happy sucking!!
*hugs*
Mae