If I have my bow square handy I use the short arm against the throat method. However my bow square doesn't measure accurately and is about 1/16th over what the actual measurement is.
It's an inexpensive aluminum one I've had since I first started bowhunting back in the late 80s. So even if it's a tad off, it matches it's owner and I see no need to replace it.
If it's not handy my school teacher wife always has a ruler or two in the junk drawer and I often use one of them.
My fistmelé is short and fat and won't reach even my shortest BH which is 7&⅜" on my latest PT longbow limbs.
That said I've told myself several times to set up the masking tape idea Dennis mentioned as I'm there too with trying to keep up.
I'm also a bit strange I guess as I can tell when my string is a twist or two off. It may be me being bs crazy but I can get that ½ twist and bam, my groups tighten up and the world is a peaceful place again.
I really like it when someone says they shoot a single string bow for the simplicity of it. That's the biggest line of crud I've ever heard.
Twist your string, trim your arrow, is the nock too tight on the serving? Nock point moved? And the twenty other things that can cause great or poor shooting results.
That's what makes it so dang satisfying when it's all right in your personal archery universe.
Or so freakin frustrating when it's not.