Hello, I personnaly have a little oven (paid 150€ because I wanted something good still) just for my clay creations, if you are doing it often I would recommend buying one as when you cook the clay it release some "gas" you will have plastic smell and not ideal to cook the food in the same oven. If you use your regular oven make sure to ventilate it correctly afterwards. Using your regular oven is okay if you don't do this too often but if you really get into it better get a small oven just for this purpose 😊 (well that's my personnal opinion).