Introducing a new feature in which our frequent-flying and unnamed executive reveals the best – and worst – places to shop, from Rome to Rio.

I arrived in Turkey after a long, rainy weekend in London spent huddled up with a team of students at the London School of Economics. My flight was a few hours late, but the sunshine in Istanbul helped me forget about the 15 meetings, five working lunches, and four business dinners planned for the five-day trip. Besides, I had another, off-piste plan.