what is the best?

There is no single approach that is "best" because we all have our personal preferences. If you want to use the deep litter method, you need to put something down that will compost, like shavings or hay/straw. Personally, I never liked the idea of putting fresh bedding down on top of dirty litter, so I use sand in my coop and use a reptile litter scoop to clean the droppings out of the sand daily. I also like to spend a couple of minutes a day cleaning up, rather than having to face a long, nasty cleaning job once or twice a year.

With hay or shavings, you do have to replace the bedding when you do your big cleanouts. With sand, you'll lose a bit over time but most of it stays put and doesn't need replacing...or at least in two years that's been my experience.

Different strokes for different folks!