Parakeets prefer non-round cages. As with any bird, the bigger the cage the better. The perches should be of various diameters for optimal foot health. Try to provide at least three different perches on three different levels. Wood perches are better than plastic perches.
Parakeets enjoy chewing and can ingest some of the plastic.
One of these perches can be a swing. Keep the swing and perches away from the food and water dishes. You want to keep the bird from eliminating in his food or water because this is not healthy. Provide your parakeet with plenty of parakeet safe toys. Birds are intelligent animals and require mental stimulation.