In order for any instrument to be playable, it must be fitted with pegs, fingerboard, bridge, tailpiece, soundpost, and endbutton. Installing these components are the last steps in finishing an instrument.

The quality of the fittings and setup will result in the best possible sound and ease of playability. An instrument with a poor setup will be difficult to play and not sound to its fullest potential. Fittings include the chinrest, tailpiece, endbutton, and pegs.

A variety of woods are available for the fittings, but ebony, rosewood, and boxwood are the most common. Each of these woods is available in different qualities. The best quality will be the most expensive, but will be aesthetically pleasing and wear better through the stresses of playing. Expensive instruments typically are fitted with the finest materials available.

The setup includes installation of the fittings, soundpost, bridge, and planing of the fingerboard. Attention to the setup varies, but usually follows along with the quality of the instrument. Due to the responsive nature of finer instruments, they will be influenced more by subtle changes in the setup and therefore need greater care. Even the finest instrument will not sound to its fullest potential with a poor setup. Likewise, an inexpensive student instrument cannot be made to sound like an original Stradivarius with even the best fittings and setup.