Every time I do this for real I cut two thin bits of insulating tape and fix them round the 'i' finger nail; the first bit goes round the underside and the other on the top side of the nail and wraps around, fixing tight as possible. Otherwise its vulnerable to serious damage! The other nails don't need this, for me. A 2nd application is often needed during the evening.
Simon Ambridge Series 40 (2005)
Trevor Semple Series 88 (1992)
Louis Panormo (1838)
Alexander Batov Baroque Guitar (2013)