The minute you become convinced that you're God's gift to a woman's vagina is the minute she's off complaining to her friends that you're not attentive/kinky/exciting enough. So, a word of wisdom: Never go into maintenance-mode with the woman you're lucky enough to regularly roll around with.
We're not saying sex should be hard work. But if you're approaching sex like it's a mission that must be completed, you're misguided. It's a new adventure each time, meaning you should be constantly seeking new ways to enjoy each other. Like any part of your relationship, it requires you to check in with each other to make sure your needs are being met. This means you should be brainstorming ways to keep things thrilling. You should be talking about your sex life, even when you're not in bed.