Cut several branches from a rosemary bush, or buy fresh rosemary at your local market. Shake each piece vigorously to remove insects and dead leaves.
Rinse the rosemary in cool water and blot thoroughly with paper toweling.
Separate each sprig from the main rosemary stalk. Remove any damaged leaves.
Preheat the oven to 170° to 180° F. Arrange the rosemary sprigs in a single layer on a baking sheet.
Place the rosemary in the oven. Leave the oven door slightly ajar to release moisture.
Allow the rosemary to dry in the oven 2 to 3 hours. Check every half hour. You may have to turn the pan once or twice to ensure even drying. The rosemary will be brown and will crumble when handled when it is ready.
Remove the rosemary from the oven and allow it to cool thoroughly. Store in zip-lock bags or airtight containers.
Line up the two squares of fabric, right sides together. Sew along the edges of three sides. Tie a knot and break off the thread. Turn the sachet right-side out.
Fill the sachet loosely with dried rosemary.
Tie the bag tightly closed with the ribbon. Use the sachet to freshen drawers and closets and to repel moths. You can also slip sachets into the pockets of coats before putting them away for the winter.