There really is no easy way to create a route. It's time consuming, and requires a lot of attention to detail. After creating a map using TransDEM, the first thing I do is adjust the track to create smooth curves, and straight sections. Then I install the grades, which can be a difficult job. Rather then using a ruling grade between point A and point B, I set my grades to follow the existing terrain. When complete, I don't touch the Smooth Spline Height tool yet, but instead, open the Topology menu, select the widest radius, the lowest sensitivity, and starting tapping the mouse to raise or lower the terrain until the track is barely visible. Now I use the Smooth Spline Height tool to smooth the terrain. I do this for the whole route, and then I go back and check all of the grades to make sure I haven't missed a section of track with too high or a low grade. The last thing I do is run a consist the entire length of the route to make sure everything is OK.
Now comes the important part of the construction. I take a 10 or 15 mile section, and completely finish it, so that it is DLS ready or whatever method you prefer to distribute it. Over the years, I created a 25 item typed checklist that I use to construct each completed section. If you don't follow this method of construction, and start jumping around from one area to another, you will have a lot of loose ends, you could lose interest, and never finish the route.
Of course we all have some days when our enthusiasm level for route building is blah. When this happens to me, I open the route and force myself to start building. It doesn't take long to get fired up and then spend the better part of the day working on the route. There are two things that have kept me going since I uploaded the Cumberland to Connellsville route in 2006. Firstly, I enjoy route building tremendously. It still amazes me to transform a terrain generated map into a finished product, and secondly, I enjoy sharing my routes. If I couldn't share them, I would never finish them. Several years ago, I converted all of my routes to DLS content only, and uploaded them to the Download Station. This way you don't have to spend a lot of time looking for missing content.
I'm not much of a train runner. Most of my operations in Driver are for testing purposes, but I'm very much aware that a lot of trainzers are interested in prototype style operations. Over the years, I've seen quite a few nice routes that are not industry related. All that you can do is run trains. For this reason, I try to add a lot of multi industry related content to my routes for those that enjoy this type of operation. To save time, I created a lot of copy and paste items that I use over and over again during construction. Several years ago, I set up a 6 baseboard map with all of the different copy and paste items, and content that I use on my routes. I called it Mergeable Content Map. When starting a route, I merge this map to the route, and when completed, I delete the baseboards. The map has now grown to 12 baseboards, but is easy to delete, and saves a lot of construction time.
Lastly, if you are seriously considering route creating, I strongly suggest that you invest in a copy of TransDEM. IMO, 50% of route appearance is TransDEM related. Some users feel intimidated by the program, but once you start using it, you'll find it very easy to work with. It has several excellent tutorials, and support is readily available in the Trainz, and TransDEM forums. I started using it when it was first introduced, and over the years I acquired a folder full of problem solving content that I copied and pasted from the forums.
If you enjoy building routes and sharing them, then you are probably a candidate for route building. I'm in my 17th year of Trainz, and I can still say that my enthusiasm has never waned.
Good luck,
Joe