In a previous life, we owned a few restaurants. I've cooked more eggs than I care to admit.
For an order of the fluffiest scrambled you've ever had, take three eggs, good splash of cold whole milk, and whisk until the eggs are incorporated. Do not overwhisk or they will not cook up right. Stop whisking the moment the eggs and the milk is fully incorporated.
In a hot skillet, melt a small pat of butter and then pour in your eggs and let them cook. We used to use pre melted clarified butter which is the best. If you don't want to go through the hassle, just a little regular butter will do. The key is to not overwork the eggs. Only stir, or better yet, fold and gently break up, when the eggs start to solidify. Carefully cook the eggs, slowly folding them until they are finished to your liking. Once all the liquid is gone, pull from the heat and plate it up. If you cook for too long, the eggs start to get wet again and then you've gone too far.
Also, use a good quality skillet such as an all clad. You really need a quality skillet for even heat distribution. If your skillet isn't that great, your eggs will not be that great either.
Don't put baking powder in your eggs as you will end up with a metallic taste.
