You need to learn to listen to her body. Read the messages she sends you with her breath, with her movements, with her sounds, and with her hips.
What guys should do in bed for having a better result.
Keep in mind:
All women are different. Every single one of them so, what works for one, most than likely, will not work for another. We, men, tend to get lazy about sex as we get older. We get complacent, we know what works for us (position, angle, mood-setting, etc) and we end up forgetting what she likes or wants. That could lead to trouble.