Begin with the report settings
Record which version was checked and whether quotations, references or small matches were excluded. Settings can change the displayed percentage. Comparisons between reports are misleading when different files or settings were used.
Inspect the passages rather than only the total
A short uncited passage can matter even when the overall score is low. A correctly quoted passage or a bibliographic entry may produce a match without the same concern. Review the origin of each meaningful match and whether the manuscript makes attribution clear.
Correct the scholarly problem
Use quotation where appropriate, accurately cite the source, or explain the idea in your own words after understanding it. Changing words mechanically does not resolve an unattributed idea. For reused material from your own publication, check disclosure and reuse requirements.
Keep a revision log
Record which passages were reviewed and what changed. Recheck the final version if required, but do not promise a universal “safe” percentage. The responsible institution or editor evaluates the manuscript, not a number detached from its context.