The classic lemon drop actually involves putting the lemon wedge along with a sugar cube into the shot. Then float some Bacardi 151 on top of it all. Apply fire and the sugar will carmelize making a tasty and slightly warm mixture.

When I was bartending this was my shot for birthday boys/girls. Pouring the Bacardi 151 so that it splashes all over the bar also create an impressive pyrotechnic effect and helps to ensure proper tipping.