Basics – replace strings regularly, use graphite in the beds of contact in the bridge and a nut fingerboard, keep these beds clean.
Most strings with regular use should be replaced every 3-4 months in professional playing and 6-10 months in students because they lose a large part of the most recent 6-10 overtone that provoke the presence of luster and its responsiveness. The period depends mainly on how often you play and what is the endurance of the model strings. When the time comes for change, never replace all the strings at once, because it would change the position on the bridge and that of the radical change in the sound of the instrument. When replacing always clean and lubricate the beds of the string, the string bed in the bridge and in the nut with soft pencil, 3B or more. This will extend the life of strings and alleviate their vibration. Replace strings in each subsequent hour when previous string began a little more to keep adjustment by setting a few times to the appropriate tone during this time. Cleaning the strings described in topic 2 extends life and improves sound, in topic 7 tuning pegs is another milestone when changing strings.
New strings are stretched and need frequent re-tune for about a week. When tune strings do not try to upload tons above relevant, as it will stretch the limit string, which will reduce its life.
There is a wide variety of model strings. Many violinists like Thomastik Dominant strings because of their responsiveness, speed of response and richness timbre. Other favorites are Pirastro Evah Pirazzi, Thomastik Infeld, Thomastik Vision, D’Addario Kaplan, Pro Arte, Zyex … Strings with a core of synthetic nylon fibers tend to have a softer sound and can keep good sounding for a long time. Each violin has its tonal qualities and therefore works best with certain strings, so experimentation and experience will help you choose the best for your instrument.
Do not forget to clean rosin from strings often!