aliciajamesmusic does a great job of illustrating how to do loose two strand twists. The difference between doing your twists loose versus tight come down to volume. You will experience much more volume when in this state, especially if you started with stretched or blown out hair . I really like the look and the length you can achieve with this method.
This can be a good protective style, though I would think you would be able to leave tight twists in longer than these loose ones, just an fyi. But it is truly beautiful.