Chop the watermelon without rind into big chunks.

Remove the seeds if any. It is advisable to use seedless watermelon. Also always use chilled watermelon to make juice.

take it to the blender, add lemon juice, salt and sugar. My watermelon was sweet, so I skipped the sugar.

Blend it till smooth and totally pureed.

Remove it to a serving glass.

If needed you can add ice cubes in the glass as well.