Oven temperatures aren't consistent throughout your oven; some areas are warmer, and some are cooler. The best way to reliably know where those hot and cold spots are is to make an oven map, and shredded coconut on a baking sheet is perfect for the job.
The Kitchn suggests using shredded coconut to figure out the hot and cool spots in your oven. Just spread some out a baking sheet pan and place it in a preheated oven.
You'll be able to tell pretty quickly where the warm and cool spots are — the shredded coconut will brown faster in the hot spots, and stay white longer in the cool ones. The method is similar to using bread to map the hotspots in your grill.