I would say it's important to drive calm and smooth. Look far ahead, and reduce the speed in front of roundabouts and intersections early enough that you can just let go of the accelerator, and not brake. A common problem is that while you are braking enough to stop in front of the roundabout, your might be approaching quickly enough for other drivers to think you might not yield.
This is also applicable for speed reductions in front of turns, reduce the speed by letting go of the accelerator, not by braking. And do it early enough. Smoother, safer and more economical.
If the sensor moves his foot and touch the brake pedal, then you have basically failed. He/she needs to feel safe at all times. Don't let him wonder IF you will slow down in front of a turn or a roundabout.
Good luck!