Uhhhm… then what am I supposed to do? Hold his load in my cheeks until the appropriate time has passed so he doesn’t feel like a piece of shit? Exactly how much time should pass?
Some other tips:
• Breathe through your nose. This helps with the gag reflex as well.
•Testicles are nature’s way of saying, “Put your other hand HERE!” Listen to nature.
•“Balls in my mouth” Don’t forget those guys. They like attention too.
• Shower blowjobs are really nice and the water helps in case you have dry mouth.
•Some men really like to look down at you while you’re sucking them off. I’ve yet to meet a man who wasn’t turned on by him standing, me kneeling on the floor in front of him. It makes them feel all powerful or something.
•I understand that giggling, humming, or moaning produces vibrations from the vocal cords that feel pleasant on the penis. I wouldn’t know; don’t have a dick, but I seem to get positive feedback from that.
I tend to use BJs as foreplay because I hate to waste a good hard on that I don’t get to benefit from. Look, he’s up! I’m ridin’ that thing, BJ or no.
I do not like to give blowjobs after vaginal penetration. Sorry, but I’m straight and I just don’t care for the taste of pussy, especially my own. I explained this once and my BF got up, washed his dick, rinsed out his mouth, and came back to bed with an expectant grin on his face. I obliged. 
And now, tips for cunniglingus:
•The only thing that’s important to me, really, is that a steady pressure and rhythm are used. If you change placement of tongue (after you’ve found the sweet spot) or change rhythm, I have to start all over again. For many females, we have to build up to orgasm (maybe everybody? I dunno). If he has found the pace, pressure and rhythm that’s hitting all the right notes for me and changes that, I go from “right there” to “aw, start over”.
•Shave. Please Stubble hurts.
• YMMV, but I don’t like to get off that way. I prefer to have a dick inside so I have something to clamp down on when I finally make it to orgasm. For me, that is the entire point of sex; the clamping down part. That’s what satisfies me. So, if you’re going to get me all the way off orally, then insert a couple fingers for me so I have something to clamp down on. I’ll let you go when the screaming stops; no worries, you won’t have to gnaw your own hand off to get it back. 
• Oh, and cut your nails. Nothing kills the mood faster than having your delicate girly bits sliced to ribbons by some careless jerk’s long-ass sharp fingernails.
•If you manscape, I’ll be happy to mow the lawn and trim the hedges myself. I prefer it that way, but I understand that nobody really wants a mouthful of muff.
•That alphabet thing? I don’t know if it really works or what. I would think not, because placement of tongue, pace and rhythm would change with each letter. Might be an interesting sensation and feel good, but probably not consistent enough to get me off. I’m not aware if anyone has tried that on me.