During my first pentest reports it happened a few times that I suddenly realised that I hadn’t saved some data which would have been good to include in the report. Usually this costs you only time to reproduce the problem and gather that data again, but sometimes it’s not possible. Either you are not allowed to access the target system anymore or in case of a test environment it might not be even running anymore. In this case you need to accept that your report will be worse as it could have been. To avoid these situations I tried to summarize for myself what is needed to a report and how all relevant data should be stored for a finding. Bear in mind that usually every penetration tester has their own way to keep their data so this here is just my way(or the highway..).