What about special attachments to the razor, like a sideburn trimmer or eyebrow reducer?
As the condition progresses, the two bare patches may meet, leaving only a ring of hair from one sideburn, across the back of the head, around to the other sideburn.
Hair clippers are also an excellent tool to have on hand for small grooming needs, such as sideburn or nose hair trimming.
This is a handy tool if you don't need the full functionality of trimmers, but need to do some facial grooming such as evening a sideburn or trimming a moustache.
Add two slim braids at each sideburn and you're done.