Click on the button "New Route" in the upper right corner and choose "Start with blank route". You can also use an existing route as a template, just navigate to this route and then select "Use current route as template".
You can navigate within the map to a specific location by inserting the location in the search box. Then you can start drawing by adding route points.
The route editor provides two different tools for drawing your route:
The magnet tool is an awesome feature as it calculates the optimal connection by bike when you insert two points. This enables a fast and easy drawing of your personal route.
Additionally it is also possible to draw your route by hand. By clicking on the pen you switch to the line tool with which you can choose the exact way regardless of roads and paths.
You can click on the blue line and drag it to insert a new route point into the existing route.