There are so many ways to cut a watermelon, but I prefer to cut it my way which is more efficient, less wastage and at the same time this method also removes most of the seeds from the flesh.

What you need is a cutting board, a knife, a container to store the pieces and of course a watermelon.

Step 1: Cut and Remove the End

Make a clean cut and remove about 2 inches from one end. This portion may not be so sweet as the middle portion. you can keep it aside and eat it latter or make juice.

Step 2: Cut a Slice

Cut a width of about 3/4th to 1 inch thick slice from the end where you have already removed the end

Step 3:

Insert the knife between the red and white portion of the slice and cut around the flesh in a circle. Now you can easily separate the rind and the flesh.

Step 4: Cut Cubes

Place the flesh on the cutting board and make longitudinal cuts about one inch apart from each other.
Make perpendicular cuts to the earlier one which will make watermelon cubes.
You will also find that most of the seeds have been separated from the flesh on the cutting board
Remove one or two seeds which may be still attached to the cubes and store in the container

Simple and efficient. There is no loss of flesh as well not much of the juice. Enjoy your watermelon cubes...