Winterizing the pool is what you do to prevent ice damage to the pipes and equipment. So, the best way to prepare your pool obviously depends on whether your location receives a heavy snowfall or it is relatively warm.
Deep clean the pool: Scrub the pool vigorously to remove all algae spores and sediments. Then, vacuum the pool.
Test the water: Test for pH levels, balance the water chemistry, and add winterizing chemicals, algaecide, and others.
Clean the filter: Clean the filter and blow out your lines correctly. Or, you may need to use antifreeze – but check the temperature rating on it first.
Remove pool accessories and some water: Reduce the water level to just below the tile line and remove the ladders, rails, etc.
Shock and cover: A few days before closing, shock the pool and run the pump overnight. Shut off the pump. Close the pool by installing a winter cover, or a safety cover for added security.