Good advice from a sex-writing tips article, though I’d broaden it to suggest avoiding dumb-shit comparisons of all sorts:

Never compare a woman’s nipples to:

a) Cherries.

b) Cherry pits.

c) Pencil erasers.

d) Frankenstein’s bolts.

Nipples are tricky. They come in all sorts of shapes and sizes and shades. They do not, as a rule, look like much of anything, aside from nipples. So resist making dumb-shit comparisons.