Here are a couple more things on the technique front.
Some of them are probably old hat to you, but there might be a guy or two out there who hasn’t heard. Let her breathe. Although some amount of asphyxia can be an enhancement to pleasure for some people, it probably isn’t for your wife, especially when it is the involuntary variety. Keep most of your weight off her diaphragm by holding yourself up on your arms. This is really crucial for those of you who have a pot belly (or if she does), because pressure on the abdomen tends to press excess flesh upward toward the heart and lungs. You want her sex organs to become swollen and tight, not her bronchial tubes.
Unless you and she are both fairly skinny, just holding yourself up on your elbows is probably not going to be enough. One excellent trick to help with this potential problem is to put a firmish pillow under your wife’s bottom, so that her sex is tilted upward toward you (this can make clitoral contact easier, too, for some physiologies) and there can be a bigger gap between your chest and hers when you hold yourself up on your arms. (One of my silly little thrills in sex is to run my hands along my husband’s triceps — the muscles on the back of his arms — because they’re rock hard when he’s holding himself up that way. Very manly-man and sexy.)
Here’s an interesting position you might want to try if your penis is long enough and your wife is not overendowed with bottom. Start in reverse cowgirl (woman superior, facing away from the man) and then have her (very carefully and slowly, or you’ll slip out!) lie back on your chest. You can then reach up and around her front to her breasts and her clit and bring her off while you’re inside her.
If you get a crick in your neck during cunnilingus because you’re lying flat between her thighs and your head is tipped back too far, try pulling her bottom to the edge of the bed and kneeling in front of her, so that you can address the job more directly and there isn’t so much reverse flex tension on your neck (this is good advice for women doing fellatio, too.)
Doggy style might be more fun for her if you use a cock ring that can provide more stimulation to her labia and, directly or indirectly, the clitoris. Many women don’t get as much physically out of doggie (although psychologically it can be very exciting) because their clitoris is so far away from the — ahem — seat of the action.
I forget whether I mentioned the comical, mood-killing noises of vaginal flatulence earlier, but one way to avoid it is to minimize the number of times you pull your penis all the way out of the vagina in a given encounter. Each time you pull all the way out and then plunge back in, you’re pressing air into the vaginal cavity, and eventually it’s going to have to come back out again.
You’ve probably heard a lot about how you’re supposed to be all gentle and sensitive and everything, but for many women a little vehemence and “selfish” aggression are welcome at some point in the proceedings. Nobody likes to feel that their sexual responses are being observed dispassionately or that they are being stimulated in some remote, calculating fashion. Just as you would enjoy seeing your wife let herself go, most women prefer a man who isn’t too controlled (or controlling) when he’s having sex.