I've found that most of my begging really only involves the word "Please".

I've done the pouty look with the "Please" and that doesn't always get a positive response. It sometimes gets a firm "NO". It really depends on the mood He's in.

The best "Please" seems to be when I'm on the verge of desperation, and there is a pleading, crazy look in my eyes (I assume), I'm whimpering with need and have a hint of hysteria in my voice.