There are a number of problems that you commonly see in throwers...

• Throwing like a girl
• Pushing the ball
• Shot-putting the ball 
• Top-down throw
• Lack of Separation 
• Flying open with the glove
• Pulling the shoulders around with the glove-side arm
• Not stepping directly at the target 
• Not stepping forward
• Not stepping forward with the correct foot
• Not getting sideways to the target
• Hyperabduction