I have a one mile climb with a somewhat steady grade that I use. I time each one and try to keep the last one "close" to the same time as the first one (actually use wattage but time will work as well). This keeps you going steady and helps you learn your body. I will generally do it 5 - 8 times. Other times I will do two minute hill repeats and a much higher speed to help me with the shorter climbs.