First and foremost how to prevent negative energies from entering the aura of your Veena?
Before anything else it's of utmost importance to make sure that the player's pranic energy which is contained in the instrument is undisturbed and pure. The following steps have to be taken in order to maintain the exclusivity of one's Veena.
1) As far as possible try not to let anybody to 1.play, 2.carry or even 3.touch your Veena.
2) Of all the above points number 1 is most significant and has to be implemented at all costs as there is this danger of infiltration of different energy, whether good or bad.
3) Female Veena artists to avoid playing, carrying or touching the Veena during the 4 or 5 days of their menstrual cycle. This causes disturbance of the purity of energy within the Veena. Apart from this the player's exertion of abdominal muscles while playing could lead to excessive bleeding and weakening of the uterus.
4) Point 3 causes serious blockages in the functioning of kundalini.
5) To remove drishti (nazar) of the Veena after every performance by circling the instrument with rock salt and lighted camphor (thrice anti-clockwise and thrice clockwise).
6) Before acquiring Veena, finding out whether the wood is pure Jackwood or not. A clairvoyant has the ability to feel the types of energy and wood of the Veena by merely gazing at the Veena, or even by running his/her hands over the instrument.
7) Using a dowser by a practitioner is also recommended. This will ascertain whether the Veena contains negative energy or not. Can any Veena contain negative energy?
This brings us to the topic of Tantriks who use Veena as a medium for attracting (vashikaranam) and black magic.
Please note that the above points are not applicable to electric 'Veenas'.