Review classical double bass pizzacato technique: turn your wrist in slightly so the thumb is a little bit under the fingers of the hand and articulate the notes a little bit to the thumb side of the index and middle fingers instead of straight on, and slightly curve the hand and fingers, thinking more press than pluck, like you are "drawing out" the tone from the strings. This does several things:
1) it keeps the articulation from being harsh, like a harpsichord jack plucking the fingers compared to the smoother articulation of a felt covered piano hammer;
2) it evens out the difference in length of the index and middle fingers a little bit so that there is more inherent consistency;
3) it keeps the hands relaxed, which also improves consistency and overall tonality.
1) it keeps the articulation from being harsh, like a harpsichord jack plucking the fingers compared to the smoother articulation of a felt covered piano hammer;
2) it evens out the difference in length of the index and middle fingers a little bit so that there is more inherent consistency;
3) it keeps the hands relaxed, which also improves consistency and overall tonality.
then doing the same with single fretted notes on each string, before working into moving up and down the string.