The city I live in is an interesting shape. Very good for running. In it is almost shaped like a hand with different fingers sticking out. Most of my runs involve running from my house to around one of the "fingers". Sometimes, if I am feeling great, I will boost my mileage by adding more than one "finger".
I have added all the mileage if I run all the fingers and it comes to 12.9 miles. Very close to a half marathon. I can easily add the distance to make it a perfect half. I am starting add the last of the fingers to my runs. The first is 2.7 miles which brings back to near the beginning of my usual path.
I just pick up and continue on normally. The second is about a mile loop that will bring back to my usual halfway point. One of my "if everything goes right" goals for the year is to run the entire length. I am slowly getting there. The puzzle is almost complete.