Now we'll look at improving a basic flat ride. A theme park is more than a collection of flat rides all lined up, or dumped in the middle of a field:
Okay, we have a "Floundering Ferry" ride. Cool for the kids, but it looks pretty unnatural dumped there on the field. It would look much better as part of a lake, or on the banks of the sea.
So using the terrain tools, I've dug out a hole and filled it with water. To add a little bit of extra theming to keep it looking good, the bits of land sticking out of the water (by accident not design) I've coloured as rocks. I've also added a beach area around the ferry. We now have a boat coming in to land. Note: I've also added the pathways.
So we have a beached Ferry. That's all right to be honest, but what if you think it's landed at a dock to off-load people. As this is a pirate area of the park, we'd best make it a forted dock. We need some kind of building to cover the queue line. Here I've just used the basic tools to quickly knock up a building:
So, it's a building. To be honest, most parks wouldn't have much more complicated things than this as they are only viewed from eyelevel by visitors. RCT3 is viewed from above though, so it's important to make things look good from all angles.
You'll notice it already has plenty of doors and windows on it, very important. Now we need to build in some detail (a stairway inside leading to the roof, and then to put the roof on top. I could have just left the rood flat, but the crenilations and guns add further to the detail:

It's worth trying to think what things would look like in the real world. So we have a relatively decent building on the edge of the sea.
Looking good? Well, it's okay, but now it needs some finishing touches. It's these additional details that really make your theming stand out.
I've finished the roof of the building off now, and added trees and low hedges to soften the entrance. Off to the side I've added a watch-tower to help add depth to the illusion. On top is a simple hut with a parrot. The ride now looks part of a themed area, rather than just something dumped down. The biggest problem? The theming covers the actual ride, which is certainly useful if it's not a very good ride.
Finally, with a bit of clever photography, you can make it look lovely:
Download the example park from here