Preheat oven to 325 degree F. In a heavy small saucepan heat half-and-half or light cream and lavender or basil over medium-low heat just until bubbly. Remove from heat. Strain through a fine mesh sieve; discard lavender or basil. Set cream aside.
Meanwhile, in a medium bowl combine egg yolks, the 1/3 cup sugar, vanilla, and salt. Beat with a wire whisk or rotary beater just until combined. Slowly whisk the hot half-and-half or light cream into the egg mixture.
Place eight, 4-ounce ramekins or six 6-ounce custard cups in a 13x9x2-inch baking pan. Place baking pan on the oven rack. Pour custard mixture evenly into the dishes or cups. Pour boiling water into the baking pan around the dishes to reach halfway up the sides of the dishes (about 1 inch depth).
Bake the custards for 30 to 35 minutes or until a knife inserted near the center of each custard comes out clean. Remove custards from the water bath; cool on a wire rack. Cover and chill for at least 1 hour or up to 8 hours.
Before serving, remove custards from the refrigerator; let stand at room temperature for 20 minutes. Meanwhile, place the remaining 1/3 cup sugar in a heavy medium or large skillet. Heat skillet over medium-high heat until sugar begins to melt. Do not stir. Once the sugar starts to melt, reduce heat to low and cook about 5 minutes more or until all of the sugar is melted and golden, stirring as needed with a wooden spoon.
Quickly drizzle some of the the caramelized sugar over custards in desired pattern. If sugar starts to harden in the skillet, return to heat, stirring until melted. Serve immediately. Makes 8 servings.