It really depends on the drivers you’re using, and in the case of A4988’s (or clones thereof), the value of the sensing resister the particular manufacturer chose to use. I was running my 3d printer on a “rule of thumb” I read somewhere that the measured vRef should be about half the current you wanted, so .7V measured for 1.4-1.5 amps at the motor. This “rule” was for DRV8835’s but that wasn’t listed in the article I read (or I missed it) so I was running my A4988 clones way too high.
As I noted above, this article got me on the right track to dialing in the proper current for my specific drivers and resisters. Things ran quieter, smoother, and cooler after I turned things down.