A drill I learned at an Alan Launder camp was to stretch a bungee across some lanes of a track. Have one end of it be about 7' high and the other about 8-9' high. Now establish a starting position, perpendicular to the bungee, to do pole runs such that your take off foot touches down about 1' before the overhead bungee. The object is to have a tall, up-jumping take off and have your top hand hit the bungee. (I recommend you grip at the top of the pole, that way your hand touches the bungee instead of the end of the pole.) As you get better with your take off, move your run a few feet sideways toward the higher end of the bungee and do more runs.
It is easy to tell if you got high at take off because you will feel your hand hit the bungee. If your steps are not on, or if you don't jump up or are not tall with your plant, you won't. This has the characteristics that Alan likes to have in a drill, it is self correcting (you can easily tell when you have done it well), closely models the actual event, and it can be like a game or a competition so it can be fun.
As I recall, the 20/20 drill was very straightforward, carry a pole and run as fast as you can for 20 meters making sure you take 20 strides in that distance. Do this with high knees and I recommend doing it on grass. At first it will be hard to get in all 20 strides so you will likely need to slow down to achieve that. But with practice you will be able to get your speed back.