Pour the lemon juice, sugar syrup, tequila and limoncello in a cocktail mixer or jar. Cover the container and shake to combine the ingredients.
Spread some salt in a shallow dish wide enough for the rims of your glasses. Cut a slit in the lemon wedge and rub the lemon around the rims of the glasses to wet them. Dip the rims into the salt.
Carefully add ice cubes to the prepared glasses. Pour the lemon-tequila mixture over the ice, being careful not to knock salt off the rims. Serve and enjoy the drinks immediately!
Notes
Chill the separate ingredients before assembling the drinks. Or, you can combine the liquid ingredients in a jar and store it in the fridge until it is chilled and time to serve the drinks.
Salt on the rims is up to you, of course. Feel free to omit it, or even try some fine sugar on the rims instead!
Looking for a frozen version? Put spirits, sugar syrup and lemon juice in a blender pitcher. Add in about 2-3 cups of ice and blend them on high to make a lemon drop slush.