Making the most of Edge 500 courses I want to make the most of this feature, and use it for navigation on pre-planned courses. I have used it two times now, and the experience was much different. The first time everything was ok, sometimes marked me off course briefly while I was riding on course but nothing terrible. 

Second time, it was way off. It would show me on different location compared to the route very often. Very often the view was zoomed out too far, and it was not clear where the turns are as everything was smashed together. I am not sure what caused this difference in experience. 

My question:

What steps do I need to take to make most of the courses feature?
Is there a way to avoid manually adding waypoints to turns, so that I can get turn directions? If not, what are the most reliable tools for creating routes with waypoints ? Any tips for these tools ? 

Finally, I saw mentions of manually setting the zoom level on the course, but no clear description of how to do that.
I've had the same mixed results using the Edge 500 for courses.

It sounds like you used a TCX file for the first course, giving you a better auto-zoom level and accuracy, and maybe a GPX file on the second course, resulting in less accurate performance. Sometimes though, it seems the little 500 just doesn't have the accuracy of other models and strays off course.

To adjust the zoom level, page over to the map/course layout and press the power/light button. You'll see the zoom level is probably set to auto. Just use the up/down arrows to adjust the zoom level and hit enter when you're done.

Generating TCX files with ridewithgps.com seems to be the most popular way to chart a course and add cues and turns. Most popular routes already exist if you search for them.

For what it's worth, the newer models, 510, 520, 1000, etc, seem to have a much better grasp on your location ( and liekly extra processing power to help ) and throw up an off-course false alarm much less often, even under dense tree cover.