Never take your cockatiel outside without the benefit of a cage or carrier. Many a "clipped" cockatiel has caught a small gust of wind and flown away. Just because your cockatiel will never leave your shoulder while he's in the house doesn't mean that, in the confusion and newness of the world outside, he won't become frightened and fly to the nearest treetop. Or worse.

If your 'tiel is out of the cage, put him back before opening up your windows or doors. Always check to be sure your bird isn't on your shoulder or clothing when you walk out the door. I can't tell you how many times I have heard, "I didn't even know she was there!" Accidents happen suddenly, and the outcome could cause you unnecessary grief.