Pots are usually not tapered well throughout the whole sweep range. In most cases, you want a gradual volume increase/decrease throughout the range of the knob as you turn it.  However, you often get nothing until the knob hits, say 7, and then you get all of your volume between the 7-10 range. It's well worth doing. It's one of those things you'll really like having once it's done. You'll find you'll use your volume pots a whole lot more if you have them trimmed for a gradual taper from 0-10.

Guitarsmith Richard Stanley says:

One thing that's nice to do is to trim the volume and tone pots. Audio taper pots are widely used in these circuits, and un-trimmed volume pots are always very fast on the top end. 50% of volume change occurs between 7 and 10 on the knob. The tone control is usually the opposite no change until you get down to around 2 or 3. The way you get the tone and volume controls balanced is to make the value of the tone control about half to two thirds of the volume pot, using audio tapered pots which have 50% of the resistance change in 20% of the rotation. If you use a 1 megΩ volume pot, use a 500KΩ tone pot, or a 500KΩ volume pot with a 250KΩ tone pot. Then to balance the action of the volume pot, you trim it by adding a resistor and a capacitor of the appropriate values across the input side of the pot. The actual values depend on the design of the pickup and the value of the pot. They're not always the same, but the average, say for a single coil circuit is a 80K-100KΩ resistor and a 1000PF capacitor. For humbuckers, the value of the resistor will be a little higher and the value of the capacitor will be a little lower, such as a 200KΩ resistor and a 400-500PF cap. This simultaneously kills three birds with one stone. It linearizes rotation and EQ, and stabilizes the signal-to-noise ratio so that when you turn it down half way, you don't have more noise.

To truly balance the circuit, you have to change at least the tone pot. More often, I wind up redoing the whole original circuit. But if you just wanted to trim the existing volume pot, on some guitars, you can do it in 20-25 minutes for less than $50. To do the job properly, I hook up some resistor and capacitor substitution boxes to the circuit and dial up the values, arrived at by ear.