When I'm creating a segment on Strava, I like to get the start and end points as accurate as possible. However, I was finding you can only zoom in so far on the map until I discovered this trick. Here's the max zoom by default, which is really coarse:
For more precision, go up to the Map menu, and uncheck
the Terrain option:
Now you're using the plain street map and you can zoom in super close to get those segment markers in just the right spot!