He may enjoy a small dish of water in his cage for bath time. A small flowerpot saucer works well. Depending on the size of the bird, even jar lids can be used. Place in the cage every few days for about half an hour. Do not leave in the cage all the time.
Some birds like to be misted with spray.
Try this a few times and see how your bird reacts. Do not mist him on cool days, as he may chill. The cage should have places where toys can be attached for the birds amusement. Mirrors are more important to a solitary bird, but even a cage full will enjoy a mirror. He will enjoy singing and looking at himself.