vids of me boxing on the bag and double and bag

[yasha]

http://www.youtube.com/watch?v=Yo0Ib...e=channel_page

me hitting the bag

http://www.youtube.com/watch?v=9Xaou...eature=channel

me hitting the double end bag

tell me what you think, what do i need to improve? what am i doing wrong? etc etc