I'm not an avid track maker but I've put in enough time with the course generator to learn how the game will cook up a section for you. Speaking of sections, 4 is a good number to play with, you don't want the track to be terribly long, I always go for lap times that are under 2 minutes in a moderately powered car, 400-500 hp. You're not making a Circuit de le Sarthe or Nordschleife. Unless that's what you're shooting for, good luck with that.
I'm assuming you're generating a course on the Eifel theme, but these tips should work just as well for most variations.
Don't get too crazy with the complexity factor or you'll end up with a track layout that resembles a bug splat. Most times 7-8 is about as high as you want to go if you want to have a nice flowing line through your sections,you can also complement the lack of complexity by reducing the width of the track and raising the sharpness of the turns. Adjust the width especially since the default setting for the Eifel and Toscana tracks makes the road way wider than necessary.
I don't usually bother with the topography of the track too much, seems to me like it's a hit and miss with how that will affect or improve the experience when you're out racing. I did manage to create a course with a turn similar to Eau Rouge once, still fond of that one.
As far as camber on the turns goes, I suggest balancing it out with the sharpness and sequence of the turns, if you want to have a higher average speed through a section where the turns are fun to navigate then play with the camber setting. I don't usually go higher than 5 or 6 on it though.
Just keep experimenting and you'll find a track that suits your taste. I enjoy semi twisty tracks with at least one full-throttle straight that leads into a hard braking corner for overtaking opportunities.
