If you want to design a safe and effective training program use the 2 essential rules listed below as guidance. Do your best to make them your priority and keep them in order. Remember, an injured athlete can't improve, or perform.
Rule #1: Reduce injury potential
No one can prevent injury. Injuries happen. It is possible however, to reduce the chance of an injury from ever occurring in the first place. As coaches, we need to accept that injuries that occur during our watch are our fault. This is especially important in a sport that only has three injury mechanisms, all of which are under our control. We should be looking to reduce injury potential during training, and during competition. Finding the right training program will keep your athletes healthy at practice, and make them more robust for competition.
Rule #2: Improve Performance
Don't forget that it's our job to increase performance. Prioritize safe, progressive training, but make sure that it's effective. Think about the risk/benefit ratio and let it guide your decision making. Think, what is the minimal effective dose? How can I get my athletes as fast as possible in the least amount of time? How can I do so without hurting them? Anytime you can load someone less (with weight or volume) and still get the same benefit, the better.
"The ideal program takes risk, but analyzes risk to benefit ratio. The ideal program works on all aspects of training but in a progressive manner that minimizes exposure to undue stress. The big key is that the program improves performance but, never at the expense of health" (Boyle, Michael. "Advanced Program Design Part 1". Strengthcoach.com. n.d. Web. 28 Oct. 2014).