Basics – use a dry micro fiber cloth, use cleaners (polishes) only from reputable producers.
After each playing, gently wipe (without pressure) rosin dust, dirt and moisture from the body, the strings and fingerboard with a soft, dry micro natural fiber cloth. Rosin remained in coils of strings prevents their vibration and affects the resonance and clarity of tone, and cleaning the area of contact with the bow provides an equal engaging your bow to the string. Left on the body of the instrument, rosin can accumulate and cause the formation of a permanent sticky areas. Cleaning should be done by luthier. These areas may be dangerous for the varnish itself, and it is an important part of protecting the Instrument against rapid depreciation and fundamental factor of influence on his sound.
In two or three weeks is good to clean in detail fingerboard (ebony only) and strings using liquid paraffin (from pharmacies), this will remove oxides and more durable dirt. Place a drop of paraffin on clean, dry micro fiber cloth with a width of 2-3 cm and carefully clean each string between the nut and the contact area with the bow, in the area of bow contact treat only with a clean dry cloth. For fingerboard place 2-3 drops of paraffin, and clean the entire area of ebony. Be careful when cleaning, do not catch the bridge, and not fall paraffin on other parts of Instrument / wipe well with a dry cloth such places!
There are many specific cleaning and polishing preparations for violin on the market. Never use commercial cleaners for furniture, solvents, alcohol or oils to clean your instrument! Do not polish more than once every few years, as this can cause deposits or limit thinning the varnish. Polishing are only for aesthetic reasons and to reduce the adhesion of rosin on the body of the instrument, and it will not improve the sound of the instrument. Instead, use your breath and soft micro fiber cloth, it will help to bring the natural glow. If you do decide to use polishes be careful, do not touch any strings or the hair of bow, as this will cause damage, which interfere with the correct sound of the instrument.
Do not use water to clean your instrument!