Not sure you can pull all that off in 15 seconds.

More like 14 sec trying to find the right hole and then 1 sec of being inside it.

Hahah, just kidding. Well, not really. Anyway, there's no real crash course on how to sex. Try "She comes first". Free ebook. It should at least give you a clue.
Also learn what a gspot is and how to hit it.

Fine, here's the rules.

1. The clit is sensitive. Do it wrong and it feels like a blowjob. With teeth. Inform yourself on how to properly stimulate it before you disappoint, like 90% of guys out there.
2. Putting her on fours will turn her on mentally, not so much physically. That's not a bad thing, just keep it in mind.
3. Slap her ass.
4. Missionary sex is like alcohol free beer. A joke. A very bad joke.
5. Spoon and jockey (or downward dog, whatever the fuck it's called) are great to stimulate her gspot. You want that.
6. Switch positions when you're about to blow. Don't ask, just do.
7. Wrap you hand around the side of her neck. That way you won't cut off her air.
8. Have exactly 1.5 beers prior to sex. No more, no less.

Prepare a music playlist of 20 songs where the average duration of each song is +3 minutes. Play the playlist in the background. You makeout for 6-7 songs. Take your time. Kiss. Lick her earlobes. Suck her nipples. Mash her breast. Rub her pussy.

When your 6-7 songs are done, go down on her pussy and run your tongue on her pussy lips. Depending on your foreplay or the girl's genetics, her clit might still be hidden from view. Take your time licking and sucking her pussy lips. Some 2-3 songs later, her clit will have appeared and grown bigger (again depending on your foreplay and her genetics). Once the clit appears, focus on sucking and licking it for 2-3 songs or until her entire body quivers. I said quiver; not shake. Learn to distinguish between a genuine orgasm versus a fake one during the initial stages.

When that happens, she will try to push your head away. Force your head through and keep on sucking her clit. This time, you insert your finger(s) and stimulate her g-spot as you suck on her clit. You're doing it right when she presses your head to her pussy some more. So from pushing your head a few moments ago, the girl is now forcing your head for more pressure on her pussy. Keep on doing this for 3-5 songs.

When you have done all of those, put penis in the vagina. You can't get it perfect the first time but by making sure she cums first at least 3-5 times via pussy eating, the odds that she will have multiple vaginal orgasms through your penis shoots dramatically higher.

You make it sound so much like microwaving food. PING.