Think of the old cliché about the mind being 'an excellent servant but a terrible master'. This, like many clichés, so lame & banal on the surface, actually expresses a great & terrible truth.
As a rule of thumb, I'd say one cliché per [Romance]--and then be damn sure you can make it work. But if you're going to try to write the virginal amnesiac twin disguised as a boy mistaken for the mother (or father depending how well the disguise works) of a secret baby, honey, you better have some serious skills. Or seek therapy.
Oh I know it's cliché but yeah they say that great men make it in- To places few others who even do take the risk've ever been
There are no atheists in the foxhole.
All novels are sequels; influence is bliss.
The great works of culture have it in their power to clear mental confusion, they give us words for things we had felt but had not previously grasped; they replace cliché with insight.
One of my mentors schooled me on branding before it was a cliche term in the game.
He is forever poised between a cliche and an indiscretion.
(A Foreign Secretary) is forever poised between the cliche and the indiscretion.