There are a number of things you can try which really helps...
First get yourself down on the ground using the ALT+Y. This will give you a close to eyelevel view of your virtual world so you can sight out and survey. You move the camera using the arrow keys and mouse. When you see a point where you want to put track down, press ESC to bring you back to editing mode. At this point, place a tall object. I use one of the old billboard trees which are brightly colored. This stands out like a surveyor's sighting beacon, and I then put myself on the ground from that point and sight out the next target.
Keep in mind that railroads generally like to run fairly flat so they will grade up slowly and then level out before they climb some more. In the process of avoiding the steepest hills and outcroppings, and climbing up the grade, the railroad will curve in long sweeping curves. They may even tunnel through and cross a ravine on a fill or bridge to keep the route smooth and flat. When I'm grading, I won't use a grade more than 2.0% on my main line which is pretty common around here. Other lines might be steeper where they run short trains such as a single or a couple of boxcars to a factory, or strictly passenger commuter service.
Now to keep your track flat, so it doesn't bump all over the place like the "Toonerville Trolley", you need to lock the track points. While in the track objects pull-out, click on the advanced menu (it pops up below). Click on the height adjustment tool in the upper left part, and then click near your spline points to level the track. The spline circles will turn yellow once they are locked. Periodically check the grade and adjust the height of your track splines so it's not too steep, if you want. The grade measuring tool, also on the advanced pull-out menu, shows percentage. You can type in an overall percentage, but keep in mind that this only affects that section between two spline points! So rather than end up with a rollercoaster, I manually adjust my tracks. Once you get the track where you want it, press the level track button and you should have a smoothly graded track where you want it.
So you don't ruin the rest of your hard work on your route, I suggest creating a junk baseboard or two sized route to experiment on. This is also useful for looking for assets and testing out track and roads, textures, etc. Once you get the hang of the techniques, go at it on your own route.
John
When you lock the spline points, do this anyway even for 0.00 track level. This will ensure that nothing moves unless you want to do that. When route building, I tend to build the terrain using a displacement map first, or create a DEM in TransDEM. I then work my route in and around the hills to produce a somewhat, if not plausible route for the railroad to follow. I've even placed track where no track ever ran by planning routes on DEM files. My Sandy Point branch on my much bigger WIP route is a line I put in on an existing HOG DEM route from many years ago. On my current Cape Ann project, I am running a transit and small freight line in and around Gloucester and Rockport. There are plenty of steep rock ledges and outcroppings my route needs to navigate as it serves the various towns in the area along with a couple of quarry operations. This part of the route building process can be quite a challenge, but it's also very rewarding in the end as the actual route is worked out.
