Put your pearls on after applying cosmetics, hairsprays and perfume.
Remove spills immediately if pearls come in contact with food acids.  Use a soft
clother moistened in water to wipe the pearls down, then dry with a soft cloth.

After wear, wipe pearls clean with a soft cloth.  Makeup, powder, grime and skin acids otherwise will form a soft gluey substance on the string attacking both the silk string and the pearls.

Have your pearls restrung once a year.