Pour 1/2 ounce of tequila into a shallow saucer that your glass will fit into. Pour the salt into similar saucer and invert your glass and press into the tequila, count to ten, then into the salt.
Quarter two limes, half two limes, and slice 1 lime thinly. Juice your half limes and the orange into your shaker, then place the quartered limes into the shaker. Pour in the agave nectar and muddle the limes by pressing and stirring them with a muddler or the handle of a spoon for about two minutes.
Strain the muddled juice into a spare glass, remove the lime husks from your shaker and pour the juice back into the shaker. Top with tequila from the saucer and another 1 1/2 ounces. Place a few ice cubes into the shaker and shake for a full 30 seconds and strain into the prepared margarita glass. Add the slice of lime and serve.
