What's a sure cut method to get her screaming big orgasms whilst im down in that region.
A. Same as guys - enthusiasm will usually trump technique.
B. Do the alphabet.
C. Avoid direct stimulation of her clitoris or dwelling on it.
D. Vary a bit on how much total pressure you apply with your face/mouth. Take her hand and let her pull you in when she pulls or pull back when she relaxes. THe amount of stimulation necessary will ebb and flow. It's a cue when she's not particularly verbal.
E. Watch the whiskers. Your chin can annoy her if it's sharp whiskers. You can cup them with your other hand and rest your head on it to prevent fatigue.
F. Patience. Be prepared to be down there the length of an average sitcom. A few times I have been down there the length of an average police drama.
As far as the shower. . .well. . .a daily shower is fine. It doesn't have to be right before.
This may be too graphic (but hey, I suppose you were) but I like the scent of a woman. . .the idea you demand a shower before tells me you don't.
Let me tell you - man to man - it's an aquired taste. I felt the same way about beer when I first tried it - I thought, "Geez. . .how do men drink this stuff?" I pretended to like it when I was 17. Now I love beer. I mean when I say I love it, I LOVE IT! I just had to drink enough of it to appreciate it.
Get what I am saying?
It's the same thing with women.
You haven't done it enough to appreciate it yet.
Have another beer.