Throwing Drills for Accuracy & Strength

Question
I coach 7-8 year old boys. Do you know any drills that could teach them to throw more accurately and to throw with more velocity?  

Answer
 Throw,throw,throw! Try to have your kids throw at least 20 min every practice.Throw in 5 min. increments.Moving back every 5 min.At the 10 min mark the should be long tossing were they have to crow hop and throw.Make sure they don't start out throwing at a close range.Have them start at least at a distance where the have to put a little effort into the throw.The last five min bring them back in were they started and focus on hitting partner in the chest.