Cut bacon slices into four pieces and cook in frying pan or in oven until crispy then drain on paper towels.
Get a cookie cutter that will fit a cocktail tomato snugly inside. Use the cookie cutter to cut circles out of the lettuce and the bread.
Slice tomatoes to no more than 1/4" thick. Blot tomatoes with a paper towel.
Spread a thin layer of mayo on the bread and start assembling the tea sandwich. Layer bread with lettuce, tomato, bacon. Then repeat: bread with mayo, lettuce, tomato, and bacon to create the second layer.