Here is my layout. I have restarted many times as I worked out how to improve my design. I have tried to make it good for a large volume of passengers and a good flow of aircraft. My GA on the left has its own arrival and departure runways which I have laid out so that the departures are moving away from the arrivals. This allows for a large turnover of aircraft especially in the morning when lots of planes are leaving. I also have a departure runway for Commercial flights at the top, which again takes the planes away from the arrivals which is on the right side.
My terminal has been designed to make everything move as quickly as possible from security to having lots of seats by the gates. I do find most of the passengers sit in these waiting for boarding so the delays are minimal. I have also made a baggage bay for each row of stands and again this has made things faster. I still have lots of work to do from the last row of stands at the top, including building the baggage bay for this and I also want to upgrade the GA stands to asphalt. My airport approval is 99% at the moment so I must be doing something right