"What often happens is that guys keep the exact same thing going on... and not realizing that when you know its near you need to crescendo...."

Unless she tells you "don't stop what you're doing!" Then you're an idiot if you change what you're doing!

Try using your hand a little too...if you're tonguing her clit, use a finger just inside. Or vice-versa (make sure she's cool with you touching her clit directly first though!). Just like with guys, all tongue might not always do the trick.