I buy strips of adhesive backed china silk online. I cut strips 5mm wide or so. I then make a 5mm square for the left hand corner of my right thumb. I also cut lengths to cover the central 70% of the middle and anular.
I file my nails at 45 degrees, rounding the corners back to the flesh to stop them hooking on the strings.
There are two methods depending on the glue used (regular SG and 'Power Flex SG' which contains rubber for durability):
For normal Loctite superglue would first apply the adhesive silk to nail with a millimetre or two sticking over the edge, and the dab superglue on and let dry for a minute. Once dry I would cut the leading edge back and file back flush with the nail. Then I would dab some more SG on the leading edge for strength, dry and repeat. Finally buff down the SG. For extra toughness, you can add baking soda which mixes with the SG for more durability, but can make a mess! Without the baking soda, you may find that you need to replace these coverings after 30 minutes of the more percussive palos (bulerias for instance).
What I find lasts longer is 'Loctite Power Flex Gel Control'
which I have posted about elsewhere. I do not mix this with baking soda. It does not soak into the china silk from on top, so needs to be applied before the silk and tamped down into place with a metal needle (cleaned of previous glue to stop the silk sticking onto the needle). Doing this will cause the gel to mix into the silk fibres. Cut back, file flush, cover leading edge, dry, buff flat.
Don't forget to wipe clean the SG nozzles afterwards and keep them clean with the needle.
My own hands are naturally sweaty. I know a CG player who has dry hands (and strong natural nails
). The acidic sweat comes through the nails, and after a day or so the coverings become weaker and can be peeled of easily to repeat the process.
What can happen is the leading edge or sides lift while playing and ruin your tone. In this case I just pull them off on the fly (run my thumb nail under to shear them off) and keep playing the piece.
I keep meaning to experiment more with methods of applying the baking soda as this is very effective but can be messy. If you find a good method, let me know!