rpenmanparker 

Float is a great addition to clipless pedals. It really makes it hard to abuse your knees due to improper foot angle. Start with as much float as you can. However, excessive float can make it harder to exit the pedals since you have to twist your foot further before you engage the release mechanism. So it helps to select pedals or cleats that provide only moderate float for the long haul. You can use your experience with the amount you twist against the float to figure how much to twist your cleats. That way you can center your foot in the range of float and manage with a lot less.