A great way to improve paceline skills while limiting risks. (From RoadBiker.com Newsletter).
"With a few friends, find a hill several hundred yards long. It doesn't have to be steep. Ride up in a paceline. Work on pedaling smoothly and maintaining 12-18 > inches between bikes. Here's the key to this drill: Keep the speed low. Around 5-7 mph is perfect. Everyone should be pedaling with the same cadence. No one should be struggling to keep the pace. Low speed ingrains smooth technique. In a normal paceline, if you speed up, you quickly overrun the next wheel. If you let a gap open, it takes effort to close and this messes up riders behind. But at slow speed on a gradual hill, there's less penalty for mistakes -- and you can simply put a foot down if you make one. Trade the front position after short pulls. Just 20-30 minutes of this slow-motion drill will make you and your friends noticeably better when you're in a paceline that's traveling 3 times faster."