I ate a billion watermelons. I cut a million watermelons. Watermelons aren’t rocket science. Neither is cutting them. After doing it for so many times I had an impression that I know pretty much everything about the subject. Except, of course, a secret recipe for choosing yummy watermelons. It turns out I was wrong in my assumptions. I don’t know as much as I though I did. Here is a tip from wikiHow:
Note that if you cut along the dark stripes on the outside of the watermelon, then the watermelon seeds will end up on the outside of the pieces of watermelon, making them easier to remove.
There are a couple of other bits on that page, which I never thought about.