On a budget, weigh it — Afternoon Tea isn't cheap for what it is.
£40–£90+
Skip the abstract 'have an afternoon tea' and pick a room with a real character: the Palm Court at The Ritz is full-dress, gilded, piano-and-tiara theatre (jacket and tie, no trainers), while Fortnum's Diamond Jubilee Tea Salon is grand but a touch more relaxed. It's an occasion, not sightseeing — lovely, expensive, and it won't fill a day.