Cliché #15: when it's clear the author knows nothing of the country they're writing about

I stepped out onto the busy London street. "Crikey!" I exclaimed. "It's a beautiful day, aye!"

I walked to a flower shop and bought a dozen roses. I proceeded to pay for the flowers with a $10 bill.

If you're writing about a country you're not familiar with, you might want to research beforehand. Just a little hint.