I would definitely read this resource before you begin....it's got some GREAT information:
https://www.thefeatherbrain.com/blog/sand-chicken-coop-bedding
That being said, last summer I built a new coop and switched over to a sand/screenings mix. Screenings are a very fine gravel almost like the gravel you see in fish tanks...only it is natural stone instead of synthetic. I put this in my coop and was AMAZED at the difference. Of course, I live in the hot, muggy, Deep south and we get a lot of rain. For me, that meant smelly, moldy, fly-infested bedding when I was using shavings and/or straw. Of course, everyone has a different situation and I'm sure sand/gravel is not for everyone. But for my flock, it made a huge difference. The smell and flies disappeared. It is easier for me to clean because it absorbs the moisture from the poop (especially cecal poop) and makes it clump like clumping kitty litter. Easy to scoop up with a kitty litter sifter. My coop, eggs, and chicken feet are all cleaner.