Survey the damage in the herb garden wrought by dropping temperatures. Lemon basil has turned gray, regular basil is curled and brown, but the Thai basil seems to have stood the test. Cut it now before super cold temperatures, and hang it upside down if you'd like to dry it. You could also process it in the microwave: Take all the leaves off the stems and put them on a plate in the microwave for 30 seconds at a time, turning them frequently until they are crisp and crumbly. Another option: Put fresh leaves in the blender with enough oil to make a slurry, freeze the mixture in an ice cube tray until solid, and take out the cubes and put them in a ziplock freezer bag. Later you can mix them with hot pasta, adding garlic, Parmesan cheese, and pine nuts to make a wonderful pesto. I never add the garlic at the blender stage because it makes my smoothies takes taste strange the next day.
Check the rest of the herbs. If you harvested dill, fennel or parsley, you need to check for stowaways. Swallowtail butterfly caterpillars feed on these umbelliferous plants, so you'll need to see them through until they make cocoons. Once they're in that protective little costume, they're perfectly happy to go through the winter frozen outdoors in a protected place.
Save some seeds. Marigolds are still hanging in there, so dig around in the foliage underneath the flowers for the dried seed heads. Crumble half of these and spread over the ground, and put the other half away to plant in the spring.