When I had a bunch of samples, I just set them all out in a row, and took notes of which ones were gone first. (I also mixed up the order everyday

). I know there was no slow transition, but my baby doesn't have a sensitive tummy, so I didn't have a problem. I always make a transition when rotating foods, but for the samples I just left them out. You'll just have to know your dog. You can mix each one in slowly and see which ones she picks out. You can usually tell which ones they're most crazy about.

Hope that helps.