I probably have thousands of SH scars on both my upper thighs combined. I just cut over either the open wounds or the previously healed ones. It's easy to cut there and you don't risk hitting major arteries unless you do it on your inner thighs. I don't feel much sensation now on my upper thighs due to the amount of scarring.
I also have a big scar on my ankle and it gets covered up by my sock, though nobody really notices it when I'm not wearing shoes. Another area is my wrist where I cut vertically and had to get stitches. My watch hides it pretty well, but it'll be quite obvious if it's a long scar or a fresh red wound.
A place I don't recommend is the stomach. I have a few small scars there, hardly noticeable, but I was wearing a crop top and my colleague asked me about them.