Take the cooked crab out of the water/steamer and place them on the kitchen towel.
Fill a large bowl with cold water, and place the crabs in the cool water for 5-10 minutes. This will help stop the crab meat from sticking to the shell.
Once the crabs have cooled, remove them from the water. Use a pair of kitchen shears to snip off the tips of the crab legs so they don't poke through the freezer bag.
Tuck the legs under the main shell of the crab. Slide the whole crab into a freezer bag and seal it.
Straw "vacuum seal" trick (optional): Slide a straw into the bag and suck out the air so the bag "shrinks" around the crabs. Slide the bag down the straw as you inhale, and quickly seal the bag while you remove the straw.
Write today's date on a freezer label, and stick it to the bag. Place the freezer bags deep in your freezer.