Steering problems during take off.
This was one of the hardest things for me to learn. I was always very nervous on take offs.
I like the idea of putting the throttle to halfway and then let your brain can catch up with the speed of the plane and steering. Then, after you get the plane going straight, slowly increase the throttle, pull back slowly and "Up, up and away"!
Of course this depends a little on how long your runway is!
Mike