Sprint training isn’t something I spend a lot of time on with my athletes. I spend more time in the gym correcting imbalances and getting the athletes strong. I feel this is the biggest bang for your buck when time is restricted as they get a lot of speed and agility work from the demands of their sport anyway. Their biggest limiting factor tends to be imbalances and lack of strength. If I were to perform more sprint sessions with my athletes then these are some general guidelines I follow.
When training for pure speed, it is important to focus on the quality of movements performed during the session and not just the quantity. You will see sessions performed where guys are just going through the motions with no attention to the details of each drill. This is pointless and you are just accumulating fatigue. You want to make sure each rep of each set is perfect. Training is about trying to ingrain the correct movement pattern into the brain so that when it comes time to compete and when you are under fatigue those are the movements you naturally resort to. If you perform them sloppy at each session then when you are under fatigue, how do you expect to maintain technique and speed?
Another thing to consider is how often you perform full speed or near full speed sprints and the distances you should cover. Personally for most field athletes I would keep the distances relatively short, working mostly on starts and maintaining speed over 30 to 60m max. If they are fast in the first few steps then they can beat defenders and accelerate away from them and if they can maintain that speed for 30 to 60m then generally they finish off and score points.
After each sprint session you must focus on complete recovery. The central nervous system (CNS) is heavily taxed when performing all out efforts so to keep the quality you must recover not only between drills and sprints but also between sessions. You will learn much better when you are fresh and you will also feel it in your performance feeling a much better flow in your technique then if you done it fatigued. Speed work should only be done twice a week in my opinion with about 72 hours rest between sessions.
During a sprint workout you have to know when to call it a day. It is the same as in the gym. We call this the critical drop off point. When the quality begins to deteriorate it is time to stop the speed work and move on to something else or go home. As they say garbage work equals garbage results. More is not always better.
When sprinting, it is also important to try and stay relaxed. Personally I find this very difficult but you should try to keep the face and shoulders relaxed and maintain correct arm action. They are the biggest tips I think most people, especially athletes get wrong. Leg turnover is generally quite good but the arm action is tough to master and needs to be focused on a lot during your drills and tempo runs.
This is far from an exhaustive list of tips but hopefully it sparks some ideas on how you can best implement sprint sessions into your program if you desire to.