I use my handheld meters in "incident" mode whenever I can. I like measuring the light that falls on the subject, rather than the light bouncing back from the subject, because I know how often the reflectance of a subject can end up being different than what one would expect.

That being said, I use in camera meters, and reflectance based meters too.

The most important "accessory" for any meter is an eye attached to a brain.

You need to be able to evaluate a scene, including the subject and the light falling on it, and then use that evaluation to help determine whether to follow the meter's recommendation without change, or to make an adjustment.

Obviously, experience is incredibly useful, but a willingness to look carefully at your subject helps just as much.

In stradibarrius' case, I would hazard a guess that he is intimately familiar with how light and the surface of wooden stringed musical instruments interact. I would suggest he think about photographs he has taken in the past of those instruments - the meter readings he has taken previously, and how previous photographs have come out.

I'd bet he has an excellent eye for reflectance when it comes to those instruments, even if he doesn't realize it yet. It isn't difficult to make use of that skill for other subjects.