Foremost you must never allow the desired crescent to become aware of your intentions. When shopping for your morning crescent I find a bold affrontery is the most tactful. There is no need for introductions, make your selection impulsively and capture said crescent with matching spontaneity, offering it no windows for escape, but while maintaining a firm but gentle pressure with the restraining thumb and fore-digits let the other hand stray and return with a butter knife laden with oleo with which you anoint the said object unsparingly. Take your time, massage every surfacial millimetre of said crescent. Hopefully the crescent has already been overtly warmed by your intimations and the butter melts, but should said crescent remain coldly hostile warm it up by placing it in your pants for no specific period of time but until the butter melts. Once persuaded in this fashion, even the most wholesome of crescents will become sinfully wicked. There you have it. A crescent you can sink your teeth into. Better even, grab another for a friend.