Many a fanfic writer has wasted away their days trying to accurately describe the wondrous experience known as an orgasm…
All have failed.
There’s no way to describe it other than that if you’re wondering whether or not you’ve had an orgasm, then you have not had an orgasm.
My advice is to relax and breathe deeply, even holding your breath for a few seconds before exhaling. It’s like you’re trying to breathe every ounce of pleasure happening to your body further inside yourself. You feel it more acutely and then you have to relax and ALLOW your body to feel it (in the exhale). Men get all tight and clenched right before they orgasm, but women need to be as calm and open to pleasure as they can possibly be in order to allow their body to crest and fall over the tipping point.
Try using a vibrator against your clit. It really helps!