Hello,
If you perform an indoor site survey (your office or apartment), then it is recommended to create every new data point on the border of existing green circle (i.e. stop and click on the map every 3 meters). If you perform outdoor site surveys, you can place sampling points more rarely, but still close to existing green circles.
Please read carefully the following article, you will find all necessary recommendations there: /help/tips-and-hints-running-a-wireless-site-survey/
