Because I'm a worry-wart and I have been hatching my own chicks for a while now, the very first day they're put on that no-slip, non-adhesive shelf lining. I peck (with a finger) at the food in the dish to show them where it is, and I push their little beaks into the waterer so they take their first drinks. After the first day, I just toss a bunch of pine shavings into the brooder on top of the shelf lining. I actually use the "deep litter" method in the brooder and just keep adding more shavings as long as they're in it. If they manage to dump their water, I pull out the damp shavings, but other than that, I just keep adding shavings. If I see a wet poop, I toss a handful over it. Every couple of days I add some more shavings. By the time they're going outside, the layers of shavings, poop, and uneaten feed are a good six inches thick.
I dump all of that into the compost, shake out the shelf liner and throw it into the washing machine, clean the brooder well, and start all over again with the next batch o' chicks.
Chicks do eat small bits of shavings, but mostly they pick it off each other or play Keep Away with a nice, dark shaving, running all over the brooder trying to keep it from their brooder-mates. The winner of that game rarely eats the prize.