Your risotto is done when the rice grains are tender yet still have a slight bite to them or al dente. The overall dish should have a creamy consistency that flows gently rather than being too stiff or runny. It's all about balancing the texture of the rice with the creaminess of the liquid, achieved through constant stirring and gradual addition of broth. The final risotto should spread slightly when served on a plate, not hold a rigid shape or be too soupy.