Free tapa with your caña

Madrid is not Granada: the free tapa is not universal. But in plenty of old-school bars a caña (small draught beer, €1.50–2.50) still comes with something on a saucer — olives, crisps, a slice of tortilla, sometimes a proper plate.

Best odds: Lavapiés, La Latina, Tetuán, Usera, and the older bars off the tourist streets. Worst odds: anywhere with a photo menu or a person outside inviting you in.

Ask nothing, order a caña, see what arrives.