Add the peach slices to a blender.
Pour in the silver tequila.
Add the fresh lime juice.
Add the triple sec or orange liqueur.
Add 1 teaspoon of agave syrup.
Add 1 cup of ice to the blender.
Blend on high speed until the mixture is thick, smooth, and fully combined.
Taste the mixture and add up to 1 more teaspoon of agave syrup if needed.
Blend again for 5 seconds to combine.
Run the lime wedge around the rims of two glasses.
Dip the rims into the coarse salt to coat.
Divide the frozen peach margarita evenly between the two prepared glasses.
Serve immediately.