To make simple syrup, bring sugar, water and thyme to a low simmer in a small pot over medium heat. Stir until sugar is dissolved. Let sit 30 minutes or overnight for a more intense flavor. Strain. Cool.
In a cocktail shaker add ice, gin, meyer lemon juice and simple syrup. Shake well. Pour into two small chilled glasses and garnish with sliced Meyer lemons or zest. Serve immediately.