There is no wrong way to do a aileron roll. the aileron rol you describe though is basically a paprabolic arc. To amek an aileron look really cool you will not use any up elevator initially. As you start your roll use some left rudder at the 90 degree point, down elevator at 180 degree point, right rudder at 270 degree point, then back to upright position. This will be a true aileron roll with no change in altitude. Looks pretty cool but will take some practice. I will let someone else handle the rolling circle. I am still working on that one.