I've used only pine shavings in mine since the girls started laying, and they like it just fine. They were VERY displeased when Agway was once out of the fluffy bedding they were used to and I had to resort to a chunkier type of bedding. They laid in other places for awhile. Once the shipment arrived, I swapped it out and never tried anything else. Picky hens!
My birds never poop in their nests, so I rarely have to empty them. I just add more bedding when they've kicked enough out. Though it does get squashed down after they've been sitting in there for awhile, I reach in and fluff it up with my hand again, and plop a plastic egg in the middle of one or two of the nests. (I wouldn't bother with my older girls, but I have a silkie who is about laying age, and a crevecoeur who recently got moved back into the coop, and they need all the encouragement they can get to lay in the right place!)
I've thought about adding some herbs to the nest, since I have so many growing out back and they don't want to eat them. I'd try woodier herbs like lavender and sage, maybe a little rosemary, but I was worried that they won't like the scent in there. I'm going to try that tomorrow, though! Knowing my girls, if they don't like it, they'll refuse to lay there. I don't think I would use basil, because that's so much more fragile and prone to rotting.