Wash and trim ends of beans.
In each jar, place 1/2 tsp. crushed red pepper flakes, 1 tsp. mustard seed, 1 tsp. dill seed (or 1 large dill head), and 2-3 cloves of garlic.
Pack jars with beans, standing them upright; trim beans if necessary to ensure proper fit, leaving 1/2" headspace.
Combine salt, vinegar, and water. Bring to a boil. Add hot vinegar solution into beans, leaving 1/2" inch headspace.
Fill water bath canner halfway with water. Place the canner on your largest burner, and turn on the heat so the water is very hot but not boiling.
Place your filled jars into the canner's rack.
Lower the rack with the filled jars into the canner. Add simmering water if needed to cover the jars by 1 to 2 inches. Turn the heat to medium-high, place the lid on the canner, and bring the water to a full rolling boil.
Process pints for 10 minutes at 0 to 1,000 feet elevation; 15 minutes at 1,001 to 6,000 feet elevation; 20 minutes above 6,000 feet.