It’s surprising how little Mac users know this trick. For many people, the default volume increments on Macs are too big of a jump for many applications. Luckily, there is a way to adjust your volume in smaller increments.
Instead of just tapping your volume buttons, hold down shift, option, and then adjust your volume using the volume adjustment keys (F11 and F12 on most Apple keyboards). You will see that the volume jumps are much smaller now.
This can also be used with brightness settings by holding down shift, option, and then adjusting your brightness (F1 and F2 on most Apple keyboards).
This may be obvious to many of you, but there is a big number of people who don’t know this useful trick.