Let's see... deepthroat is unneccessary, but you should be able to get half of it in; very, very, very wet; alternating licking with sucking (alternating more quickly as you near the climax); use one hand to grip the bottom half, and keep the skin pulled taut at all times; with the other hand, keep tension on my scrotum (your whole hand will fit between my balls and my body); licking and sucking my balls would be a winner, but not near the climax (unless you were trying to draw things out); eye contact (though not every second) and obvious enthusiasm are hugely important; swallowing isn't neccessary in a casual relationship, but makes a guy who already is serious about you feel all warm and protective (I think it's an act of submission); if your knees can stand it (try a pillow), kneeling in front of me, topless and with conveniently long hair to hold is just icing on the cake (while you're kneeling like that, you can rub my wet cock over your neck and breasts, if you want to slow things down -- and the feeling of your nipples against my thighs...); and rubbing my perinium in time to the contractions when I cum wraps thing up nicely, though it would certainly require lots of practice to get the timing down.
Thank you for starting this thread, Eva!