The one advice I would give for breakfast is stay away from all grains. I am grain free. I know that is a huge step for most people. A year ago I would have called anyone doing that nuts.
But if you have protein and fat at breakfast, stellar A++ start to the day. And if you get into bulletproof coffee, I will let people google it, awesome. The old eggs and bacon, hopefully cooked in real grass fed butter, who knew? Virtually the perfect breakfast. Especially if the hogs were raised well.
Protein and fat will get you full to lunch and get your brain going. Cereals will spike your insulin and leave you feeling famished well before breakfast for many people. And for many it will put their bodies into fat storing mode instead of fat burning mode.
We were giving our three year old oatmeal for breakfast. She isn't grain free right now. Just too hard to do with a three year old. But we switched to only eggs and even bulletproof almond milk in the morning. It may be a coincidence but she has had her best month ever at school and seems much happier and just a much better listener than when on oatmeal and cereals for breakfast.