The Art of Sucking a Man's Penis (Cock), often referred to just as 'Oral.'
It takes practice and yes there variations to doing it.
Girls. the secret is making it last, and then causing the man to explode in your mouth.
Ladies, don't forget to swallow and lick off every drop, don't waster any.
Also practice taking it all the way in till you can reach your man's testicles (balls).