Not quite as long as you, but I've also been doing so for a long time. I've probably shaved my groin more often than I have my face at this point. I'm still pretty awful at it.

• I'm morbidity obese, so the reach isn't always easily quite there.
• Because of the obesity, it's really only feasible to shave standing up, but I broke my ankle and hurt my spine a while ago, so it's already difficult to stand up for any period of time.
• I'm right handed, but I've dislocated my right shoulder fourteen times, so I can't always make that hand/arm do what I want.
• I'm pretty uncoordinated with my left hand and have arthritis in that shoulder, which isn't a huge limiter, but still complicates things.

I just do my best and hope that, at worst, it doesn't itch for me and is not actively unpleasant for my partner. Generally speaking I don't expect anyone else to look at or interact with the area.