Your dough should be soft and supple. However, it shouldn't stick to the side of the bowl or be so dry that you can see cracks in it. As mentioned in Step 1, if your dough is sticky, simply add 1 tablespoon of flour and knead until it's combined. If your dough is dry, simply add 1 tablespoon of milk and knead until it's combined. Your dough may resist ingredients at this stage of the mixing. However, keep kneading and it will get there!