Hi Shane. Before I train speed, I always train deceleration! I think that too much emphasis is placed on speed and acceleration BEFORE the athlete is taught how to safely and effectively slow-down or stop. Deceleration training is the key to speed training for ALL athletes with the one possible exception being track athletes who literally run-through the finish line.
I wrote a continuing education course for the International Sports Sciences Association on Deceleration Training for Female Athletes as a means of reducing the incidence of non-contact knee injuries (most of the non-contact knee injuries are related to a deceleration event such as cutting, stopping etc).
I hope that this helps.
I train agility, explosiveness/power, and foot speed before I focus on actual speed training. Learning those different aspects of training will make speed training easier, allowing to focus on the mechanics of speed training.
Agility, foot speed, and power can be taught by using simple exercises such as toe taps, speed skaters, explosive skips, bounding, and other Calisthenics type exercises. Two of my favorite tools are the speed/agility ladder and dot mat. These tools enable you to train agility, foot speed and power, while making it fun and challenging for your client.
Power and speed can be developed by performing plyometrics, hills, and as Larue said deceleration. A form of deceleration training that I use is decline sprints. Decline sprints not only help with learning deceleration, but also help increase speed.