I generally shoot for a couple of feet past the start of the runway. For me it is the easiest to control that way. As the plane is coming towards me I will see if either wing starts to drop off, (stall) and easier for me to line up. I also have the whole runway to use. I generally cut to idle on the the final approach turn and add throttle as needed to keep the glide path good. I guess everyone has his/her own routine that they are comfortable with.