Have your players stand at 1B, 2B, SS, 3B, with 1B and 3B standing in the basepath about 2 feet from the bag. start throwing around the horn, 1B-2B-SS-3B who reaches down and tags the bag with his glove. He comes back up and fires, 3B-SS-2B-1B who tags the bag also, then repeat. Emphasize speed; the players should try to loudly pop the ball into their teammate's glove. The close proximity of the players to each other will take away their fear of throwing wild; combined with emphasis on speed, they will learn not to overthink their throw. Count the number of pops in one minute, then bring in another set of players and see if they can top it. Your players will get a great rhythm going and develop confidence in turning and firing the ball. Emphasize a smooth, continuous "catch turn throw" from player to player. If the other team sees you warming up this way, and hears that loud "pop" with each catch, they might be less aggressive on the basepath.