IMHO, what makes someone a good or bad lover is intent. If all you care about is your own pleasure, you’ll be a bad lover. Your partner will only get pleasure as a by product. If you care about your partners pleasure, then you will be a good lover, because you will eventually discover those things that you partner cherishes in a sexual relationship.
However, having said all of that, there are some couples that are lousy in bed together. They don’t “fit” together. Their tastes sexually are complete opposites. She likes a fast rhythm, he likes it slow. He likes missionary, she likes “cowgirl.” etc, etc. So it is possible to be a lousy lay with one person, but great with many others.
Not to bitch, but in my sexual experiences I noticed that the one guy who was able to make me come during “standard” [read: missionary] intercourse [sans manual stimulation] was able to do it with every girl he’d been with previously, and I assume with the ones he’s been with since. If I may get a teeny bit graphic here…
In the missionary position, it’s a matter of the angle at which he’s moving AND how far inside he goes. If the girl is on top, in front off, beside, or whatever, she has much more control than being underneath, where it’s pretty much up to the guy. I’m trying to teach this technique to the current bf because it’s just sooooo nice.
While I agree that taking pleasure from giving your partner pleasure makes for a better experience, I’ve also found that the quality of the experience varies depending on the partner. I’ve been boring for some, and good for others.
For some reason (hormone insufficiency?) I am completely incapable of getting or maintaining an erection unless I masturbate; visual stimuli don’t work, and if I take my hand off my penis, it softens within seconds!