After each use, always use a cloth to wipe dust and rosin off your instrument. This insures rosin does not build up and hurt the varnish.
When not in use, place your instrument in the case. Nearly all damage done to an instrument is when it is outside the case.
Periodically check your bridge to make sure it is standing straight and is not warping or leaning forward. The bridge should be centered between the inner notches of the f-holes and centered on the fingerboard. It should fit perfectly into the top of the instrument with no gaps.
Always keep your instrument away from extremes in temperature and humidity. When you need to replace strings, do not take all the strings off at once but replace one at a time. This will keep the tension on the top of the instrument and help keep the sound post in the correct place.
Remember that your bow is just as important as your instrument. Loosen the hair after every use. Wipe any excess rosin off the stick with your cloth.
