Cut the watermelon in half and remove all seeds by scooping with a spoon. Cube the pink flesh into 1-inch pieces — you'll need about 4 cups. This takes about 5 minutes.

Add the watermelon cubes to a blender. Blend on high speed for 1 to 2 minutes until completely smooth. The mixture should look like pink juice with no visible chunks.

Place a fine-mesh sieve over a large pitcher. Slowly pour the blended watermelon through the sieve, letting the juice drip into the pitcher. Use a spoon to gently press the remaining pulp to extract more liquid. This takes about 3 to 5 minutes. You should have about 3 cups of clear watermelon juice.

Checkpoint: You are ready to move on when you have smooth, clear pink watermelon juice with minimal pulp.

Cut a fresh lemon in half. Use a citrus juicer (hand-held or countertop) or roll the lemon firmly on the counter first to break down the cells inside. Squeeze each lemon half and collect the juice in a small bowl. Repeat with 6 to 8 lemons until you have about 1 cup of juice. This takes about 5 to 10 minutes.

Strain the lemon juice through a fine-mesh sieve to remove any pulp or seeds. This takes about 2 minutes. You should now have about 1 cup of clear lemon juice.

Checkpoint: You are ready to move on when you have 3 cups watermelon juice and 1 cup fresh lemon juice, both strained smooth.

Gently tear or lightly chop the fresh basil leaves by hand — do not use a food processor, as this bruises the delicate leaves and turns them dark. You should have about 0.5 cup loosely packed. This takes about 1 minute.

Pour the strained watermelon juice into a large pitcher. Add the strained lemon juice, torn basil leaves, granulated sugar, honey, 4 cups cold water, and sea salt.

Stir the mixture well for about 1 to 2 minutes, stirring continuously, until all the sugar dissolves. You'll see the sugar granules disappear and the liquid will look uniform in color.

Checkpoint: You are ready to move on when no sugar granules are visible at the bottom of the pitcher.

Let the lemonade steep with the basil leaves in it for 10 to 15 minutes at room temperature. This allows the basil to infuse its flavor into the drink. The longer it sits, the more basil flavor you'll get, so taste it after 10 minutes to see if you like the intensity.

After steeping, place a fine-mesh sieve over another large pitcher or bowl. Slowly pour the lemonade through the sieve to strain out the basil leaves. Discard the basil leaves. This takes about 2 minutes. Do not squeeze the leaves; just let gravity do the work.

Checkpoint: You are ready to move on when all basil leaves have been removed and your lemonade is clear pink in color.

Fill serving glasses about halfway with ice cubes — use about 5 to 8 ice cubes per glass, depending on glass size.

Pour the strained watermelon basil lemonade over the ice, filling each glass to about 1 inch from the top.

Garnish each glass with a fresh basil sprig, a thin lemon slice laid flat on the rim or floating on top, and 2 to 3 fresh watermelon cubes.

Serve immediately while cold and enjoy!