Start with place, time and jurisdiction
Start with the historical parish and language context. Finnish records may use Finnish, Swedish or Russian forms, while a person can appear under translated given names and changing surnames. Record the original form and search variants rather than normalising every entry to one modern spelling at the outset.
Follow the strongest record sequence
Use HisKi as an index to locate likely parish events, then inspect the relevant church book or population register in Astia when available. Communion and household books can connect families across years; births, marriages and deaths confirm events. Pay attention to village, farm and moving information when following migration.
Preserve evidence and local context
Cite the parish archive, series, volume, year, page or image and repository. State whether a fact comes from an index or an original image. Preserve parallel name forms and the source language, and do not collapse a guessed identity merely because dates are close or a translated name looks familiar.