I learned about drawing a "sproul line". It is an old school method used in boat making, but we used one to bend steel tube for a foot rail for a bar. I tried to research the method online, but couldn't find anything so I assume it is one of those little tricks that people don't use much anymore. I think it is awesome!
Basically, we laid down a piece of plywood (appx. 5' x 6'). We got another piece of plywood (appx. 12" x 18") and drilled a hole large enough for a Sharpie marker to go through it. We went to the bar that the foot rail was being made for for, put the large piece of plywood on the floor with 2 corners touching the bar. The smaller piece of plywood went on top of the large piece with the corners touching the bar also. The small piece was pushed along the bar with a line being drawn on it to match the radius of the bar. After using the line to match up the curve we put in the steel tube, it matched perfectly!