Using your nails
Classical guitarists pluck the strings using the fingernails. These need to be kept shortish -1-2mm above the fingertip - and shaped correctly, so that they create a good plucking action and the best possible tone. Every serious player keeps a variety of nail files and buffers – a big favourite is very fine wet and dry sanding paper. This is used to smooth off the edges of the nails and keep them buffed to a fine polish. The better the nails, the better the tone!