I am having the same darn trouble. I have 15 pullets, and I'm getting 8 - 12 eggs per day. However, only 3 of them are in the nestboxes! I have clean, comfy bedding in there and fake eggs, and they don't seem to care one bit.
At first, I just chalked it up to being new to this whole laying eggs thing, and they would take some time to figure out how to make it to the nestboxes before the eggs came out. But, they seem to have adopted two corners in particular and made them into nests. And, then, I'll find usually 2 or 3 of them randomly around the floor of the coop.
I might try blocking off the two corners that they particularly seem to enjoy laying in.
Any other suggestions?
And, I know this might seem like a really stupid question, but it is ok to eat the eggs I find on the floor, right? I make a thorough check every day, so I know they are fresh and haven't been hiding somewhere for who-knows-how-long, and I pitch out any that have gotten cracked from being walked on. I've been eating the ones that don't get cracked, though, and I just want to make sure before I start giving these eggs out to friends that I'm not doing something terribly wrong.