My baby, Chirp, feeds freely during the day on his own special mix (either dry or made into mash, depending on the day) but he has lots of foraging opportunities! He has a little set of 2 drawers that I put millet in. He loves them, but if he opens them and there's nothing in there, he'll just push and pull them in and out, again and again, to let me know he wants his snacks! I tuck bits of millet into various toys, especially ones with cupcake liners! I also tuck oat sprays in various spots around the cage, Chirp loves those!
For out of the cage, Chirp has recently started running around on the rug under and around his cage, looking for anything I may have dropped (or that he may have flung onto the floor). Even though I vacuum regularly, I don't want him to get anything that might be on the rug. So, I put down 2 towels on top of the rug, covering the whole thing, and I put little bits of millet around! He loves to run around and find treats! I also have a little plastic lunch tray (I think it was 4 dollars from MYOBT) that I put on the floor, where I put treats sometimes!