When you are modeling your projects in SketchUp, think about exactly how it would be made in real wood. That can guide you in your modeling. I extended the path off the part at each end to make sure the path and profile start and end square. In the same way you would turn the router on before you make contact with the wood and the router would come off the wood before you shut it off.
And for what it’s worth,
Woodworking is my primary use for SketchUp. A few examples.