Unless you communicate you will never know if you are actually great. Chemistry is the key to great sex. Chemistry is all about timing and communication. When I say timing I mean making the person earn and learn you. Of course, you might want to have sex with that person but do you really WANT that person? You ever talked to someone so long but there was never any kind of physical touch and that left you wondering "what would it be like?" That's when you start really WANTING that person. Communication is of course getting to know each other wants and needs. The first time everyone have sex they are being graded even if its not intentional. I agree with the older woman if you really like this person you should try and teach the person what you like.
The art of sex is all about pleasing your partner. Touching them in places they may have never been touch. Kissing them in places that set them on fire. Its not all about getting straight to it, especially for a woman. Ever kissed a woman under her navel and went back up to her neck ? That is you making her want you even more. Teasing may sound childish but it stimulates your mind. I asked a question on Twitter " Where are your hands during sex?" Believe it or not if most people look like a dummy doll during sex. Your hands on the side of you while your partner do the work. Rub and caressing your partner is pure motivation.
When your partner comes through the door don't go straight to the bed. Kiss them while their back is against the wall. Touch on them, show them that you've been waiting for that moment. If aggression is not your thing try cuddling first. Sex is great after cuddling and cuddling is great after sex. Have a intimate conversation while straddling your man before sex. Play fight it is all about being indirect at first because believe me doing all this somebody is thinking about taking it to the next level. Being around someone you want is a constant battle in deciding when the time is right. So even if he/her is over there initially for sex make them feel wanted and needed. Do not just jump to it.
It all comes down to feelings wanted. One mood killer is not being confident. Even if your partner isn't 100% confident during sex the fact that you make them feel wanted can make that all go away. Compliments during sex never hurt anyone. Everyone doesn't like aggressive sex and everyone do not like slow, sensual sex. I guarantee if you create chemistry and make your partner feel wanted you two will figure out the art of sex when it comes to you two being intimate.