If you throw something at me to get my attention, expect to get pinged in the head with that very object.
If you need my attention, either walk to me and tap me on the shoulder or if you are unable to get to me and it is urgent, waving your hands is also acceptable. Also, tapping your foot on the floor is a good way.
Yelling at me like I am an idiot is pointless - and believe me I will make sure you are the one that looks like a bigger idiot.