Look after your picking hand fingernails! It’s very important for tone production and control of technique to get your fingernails sorted. You need to work on finding the right length and angle of nail to produce a clean warm tone. The contact on the string should be both flesh of the fingertip and nail simultaneously. It can take a bit of time and experience to get it just right, then you need to maintain the condition of your nails with regular filing and polishing to keep the nail edges smooth and gleaming.