There are a number of ways to observe cervical mucus. In order to determine the sensation produced by the cervical mucus during the cycle, the woman observer needs to make mental notes of what sensations she feels at the vulva (i.e., the lips of the vagina). Mental notes should be made throughout the day, when going to the bathroom and before going to bed.
It is also recommended that the women observe the mucus. Many women do this by using soft white (non-scented) toilet tissue and wiping or blotting the vulva. The mucus can be observed on the tissue for its color and appearance. Finger testing can then be used to determine the consistency of the mucus. To do this, the woman lifts the mucus off of the tissue and observes it at eye level between the finger and thumb. When finger testing the mucus, she can also determine how stretchy and transparent the mucus is. Another determinate for the consistency is how far it will stretch before snapping, referred to as the "stretch to snap."
It is important to be consistent with making the observations on a daily basis and recording what is seen on a fertility chart. If observations are missed or skipped, there will not be a complete record of fertility. At the end of the day, after the last check before going to bed, the most fertile observation should be recorded on a fertility chart.