Yeah absolutely. I don't know how experienced you are with building, so I'll give you some general advice that is always applicable:
- An easy way to build for flow is in segments. Make the first few seconds of the map, then test, and see where your car is naturally leading at the end of it. Build in that direction for the next few seconds of the map, test, repeat. This way, you can always rely on your map being at least somewhat flowy.
- Scenery in PolyTrack is fun, because we only have some basic blocks with which to make everything with. The big differentiator for me is creating depth. A good thing to try out is to try and build a map with great scenery detail with only one colour. You'll quickly teach yourself how to use shadows, depth & shapes this way to create awesome landscaping, architecture, etc. Here is a preview of a map I'm releasing in December for the seasonal tournament, that does a similar thing (:
Hope this helps!