Post or e-mail your practice plan to your players the previous night. This allows them to mentally prepare and will help them anticipate the next drill so there's less wasted time. I am aware that every player will not read it. However, even if a third of the team reads, your practice will go much smoother as it will take away the time of you explaining what is going to happen next. A third of your team will know where to go, the rest will follow like sheep.
Your players will share your passion. If you are excited about the next drill, they will follow. If you walk around and seem unorganized, so will your team. We all have our down days, we are human. On those days ask somebody else to take the lead, a captain, an assistant, whoever, just be sure the person who is leading can have passion on that day.Injured players may not like those jobs, but what is the other option? Going home? Or just hanging out because they need to be part of the team? We all know that ends up in them being a distraction.