Each of the planetary sections has templates on their websites on which you can draw the features and record other important details. The Saturn section has a series of templates depending on the angle of the rings (which you can look up in the Handbook). See: https://britastro.org/section_information_/saturn-uranus-and-neptune-section-overview/observing-programme/saturn-uranus-and-neptune-visual-report-forms
Regarding phases,in the case of Venus the observed phase generally differs slightly from the calculated one, a phenomenon called the phase effect: https://britastro.org/2016/the-phases-of-venus. So the phase should be drawn in at the eyepiece. The time of dichotomy can be determined from your observations and compared to the predicted time.