You have two ways to activate regenerative braking. One is with the brake pedal. Best practice for high mileage is light braking (not bringing hydraulic brakes into play) long before you stop. Sorry, don't need to lecture to a Prius owner as this is exactly the same, just no B option. The other way is to use cruise control. While in cruise, reducing the speed will be assisted by regenerative braking. It also happens on downhills in cruise control.