I start by cutting the watermelon in half through its width, then set each half flat side down on my cutting board. This gives me a stable base so the knife doesn't slip while I'm working. A stable cut here makes every following step so much easier.
Next, I slice the watermelon into slabs about half an inch thick, working from one end to the other. I try to keep the thickness consistent so the fries cook evenly in flavor, even though there's no actual heat involved. Even slabs mean even, fry-shaped sticks later.
Once I have my slabs, I use the crinkle cutter to slice each one into long, thin sticks that look just like classic French fries. The ridged edges genuinely make them feel more fun to eat. This is the step my kids love watching most.
Watermelon holds a lot of juice, so I gently pat each stick with a paper towel to remove excess moisture. This keeps the fries from getting the plate soggy and helps any toppings stick better. A quick pat makes a noticeably neater presentation.
I squeeze fresh lime juice over the sticks, then sprinkle Tajín and a pinch of salt evenly across the top. If I'm adding feta, this is when I crumble it on. The seasoning is really what turns simple fruit into a snack people ask for again.
I like to pop the tray in the fridge for about 10 minutes before serving, just to make sure everything is extra cold and crisp. Cold watermelon always tastes more refreshing than room-temperature watermelon. This little chill step makes a bigger difference than you'd expect.