Basics

First, you have to make her feel comfortable. Wheter she's your lifetime girlfriend or a girl you just met, it's just as important. Don't get too eager or too pushy about it. You have to be relaxed and start off gently but passionately. Making a girl feel desired is allways good. Now, I can't tell you exactly what EVERY girl wants, cause not every girl wants the same. But usally when a girl can't come is because she's uncomfortable in some way, and this girls tend to stand in the same cathegory, so this recomendations should petty much apply to them all.

My goal here, is to make you hable to help her overcome her fears or/and problems and show her trough your enhanced lover skills that she can toroughly and exaustively enjoy sex (with you of course)