Rinse the almonds really well under cold running water and add them to the container of your high speed blender, along with the 3 cups of water.
Secure the lid and start the motor on low speed and then slowly increase all the way up to the highest setting. Blend the water and almonds for 2 full minutes.
You could drink the milk as is, but it still contains a lot of pulp at this stage. For a creamier, smoother milk, strain it through a fine mesh sieve lined with cheesecloth, or better yet, just pour it right into a nut milk bag which you will have placed over a large pitcher or measuring cup.
Squeeze the bag until no more liquid comes out.
Store your milk in the refrigerator in an airtight container for up to 3 days.
Notes
Simply cover the nuts in cold water and place them in the refrigerator to soak for at least 12 hours or up to 48 hours, then rinse them really well under cold running water.