ITS TUT MAKING TIME
First, you make a stick man going to the other side of the screen (simple)
Redrawing the stick can lead to resizing.
To fix the resizing issue, you can copy the same stick into every frame. The problem is that it makes the animation look lazy, it is apparent that you copied the same stick each frame.
To fix the copying issue, just draw over the stick again, tracing it, but leaving the original image of what you are tracing in the frame. The stick stays the same size and the animation looks efforted (if that's a word.)
I did this with easytoon, I do not have flash