We do use the tailgate mounted camera until close enough to drop the tailgate.
I also put a bright reflective vertical strip in the center of the king pin head.
Then, I usually set a medium orange traffic safety cone in the center rear of the bed. Gate down, when the cone gets to the king-pin using the inside mirror it's lined up perfectly. DW has aced this every time, leaving me to tend to the other hitching tasks.
J & J, DRV Suites ES-38RSSA #9679
GM Denali, 3500HD-Max, 4x CC, 8' DRW,
EZGo-TXT, Clubcar Precedent