High tea at Fortnum and Mason was such a fun experience. It was possibly one of the classiest meals that I have had in my life.
The lobster omelette that they served was amazing, and so were all the scones and cookies. The tea was definitely the best tea that I've had in England. I would highly suggest going to high tea while in London!
Here's a video with some information on how to have proper etiquette at Tea.