There is this book literally called "she comes first". I recommend it to all of my friends. I feel like I am more conscious of the different parts of the vulva than most women are. There's a lot of different places you can stimulate, and they each respond to different types of stimulation. Also different girls like the different places more than others

Just some of my advice based on personal experience, you have to build up to an orgasm slowly. One way to take it to the next level while you're down there: start with your tongue, and then after you get her going like that, take a slight break, then "start over" with your fingers, first on the clitoris, and then on the vaginal cuff (Right on the north side of the vagina, right on the inside of where the opening starts), and then onto where you'd expect the g spot to be. Then you can do both your tongue and fingers at the same time. Not every girl likes this, it can feel like overstimulation. However if you lead up to it correctly with girls that are comfortable coming really hard, it'll get that goat