you need to work on your balance. try to protect the ball by getting farther away from the tackle. then you'll be on your feet and the oponent on the ground.
eg: the tackler is coming from the right. get the ball left and get your body(mostly your feet) between the ball and the defender. then with your other feet(left in this case). push the ball to the starting direction before the tackle. and the ball must at all times stay near your feet except when your running on the wing and nobody is in sight