I free feed but I use Proplan. I just read that it wasn't that good of a food on here though so I am checking around. This is what my breeder fed him since he was a puppy and I have continued it.
When I feed I just fill his bowl up and he lets me know when it is empty. Usually we fill it every day or everyother day. He nibbles at all hours day and night. He doesn't woof it down.
I did buy some of that soft hamburger type stuff in a package just to mix w/ his proplan every now and then for a treat. Well I found that he would pick out the proplan and spit it on the floor and just eat the hamburger stuff