Taking care of your violin is a daily routine. Here is a list of things I do to make sure my violin is in good shape so it can produce the best sound possible.
1. Wipe off the rosin dust on the strings and the violin every time after you play. Rosin left on the strings and over the body of your violin can cling to your instrument. It is sticky and will ruin the finish of your instrument.
2. Loosen your bow after each practice. An extended period of tension can cause the bow to warp over time and lose its arched shape.
3. Change your strings regularly. A Luthier once told me the life of my strings is about three months, if I play 3-4 hours every day. You can continue to use the same strings until they break, but they won't sound as good.
4. Check your bridge's alignment. I have developed a habit of checking my bridge's alignment after I tune my violin, because tightening the strings can make the bridge lean forward. Make sure the feet of the bridge are flat against the surface of the violin, and the bridge is at a 90 degree angle with the body of the violin. If adjustment is needed, loosen the strings slightly before you move the bridge.
5. Keep your violin in a place with room temperature. Your violin doesn't like extreme temperature levels, so make sure it is stored indoors, but away from heat.
Keep your violin happy and it will keep you happy! :)