One of the biggest parts that I feel is a necessity is a flowing layout. There's definitely a natural rhythm and you can tell the difference between rides. I'm always critiquing a ride's layout, thinking about how the ride would be if the park used this element instead of the current one. Rides like Diamondback, Patriot, Fahrenheit, and The Voyage all flow extremely nicely, but there are rides like Wildfire, Raptor, Millennium Force, or Dominator, where they could have an element added, taken away, or replaced and the ride would be changed drastically.