The ideal posture when playing violin is, as one would guess, sitting up straight on the edge of your chair. This allows the instrument to be supported by your shoulder so the left hand can slide up and down the fingerboard, and finger without tension. The ideal left hand position is all fingers curved with only the tips of fingers hitting the strings. You are also not clutching with your left hand. Holding the bow with your right hand, all fingers are curved and fingers are flexible to make sure the the bow is parallel to the strings. Tuning correctly is essential to getting the correct sound when playing. Finger and hand dexterity is important because it helps us master how to quickly and accurately move fingers for each note. This can be improved using a violin by playing pizzicato with both hands.