Make sure you add some moisture, whether it's a lubricant or even saliva. The wetter, the better. If he is struggling to get the job done right, show him how it's done. Don't be afraid to teach him the techniques you use to pleasure yourself. Nobody knows your secret spots like you do. If you're riding him, lean in and rub your clitoris against his pelvis. Experiment with different sexual positions until you find ones that best works in hitting the oft-ignored C spot. Many women find that they are best able to orgasm when receiving oral sex. The bottom line is that when it comes to achieving an orgasm, sometimes it's important to think outside of the box.