Place your new habitat in a quiet area away from drafts and direct sunlight. Your guinea pig or rabbit will enjoy being in this larger area. Guinea pigs can usually be kept in the enclosure at all times. Rabbits will still need some daily exercise outside of the enclosure. Add interesting items to the habitat such as large diameter poster tubes or small cardboard boxes with guinea pig doors cut out of the sides.
Some people use large diameter plastic plumbing pipes.
Avoid objects like metal cans that might have sharp edges or small tunnels that your guinea pig or rabbit might get stuck in. Some guinea pigs and rabbits enjoy ripping apart brown paper bags or jumping over a small log. Be creative but only introduce safe, sensible items to your animal. Stick to items that are natural such as wool, unbleached cardboard, or wood. By keeping your animal's physical and psychological needs in mind, you will create a habitat that is safe and enjoyable for your animal.