Agree with all comments so far.
A few finesse tips to look at
1. Percussive notes
- I whack the PALM side of my hand/fingets against the strings for a percussive note.
- Try using your ring and pinky fingers for this, or just the ring finger and palm whilst slapping. (may as well put them to use).
That way you don’t have to keep whacking your cuticle.
- or you don’t have to straightening & bending the Index & Middle fingers to alternate popping & muting.
2. Posture
- do you slap standing? I’d love to see how your technique & bass angle/height changes.
I prefer a lower plucking hand & more vertical neck. I slide the strap on my shoulder to get this angle.
- are you hunching or often looking at your hands? Stand in front of a mirror for better posture & ease of viewing hands.
Try playing with eyes shut to see where your body feels most relaxed when playing.
3. Tape the back of your finger.
- everyone’s anatomy is different. If this is the only position, or the best position by far for your hands…. try some bandage/adhesive sports tape only over your cuticle area.
Some Double Bassists tape their fingers a lot esp Rockabilly-Slap bass style.
Thai stuff is the ducks nutts.