Rockin Rollercoaster is one of my favorites, but its also one that builds up a line fast. We generally go there at park opening, early opening if we can (early opening is one of the few perks you still get for staying in a Disney hotel) and ride it until the line gets too long. Soarin' is pretty much the worst wait in the park, late in the day the line just to get a Fast Pass is longer than the lines to ride almost anything else in the park. Our plan usually involved heading right to Soarin at park opening, getting a Fast Pass and then getting in line. That way you were pretty much guaranteed two rides.