1
Import and locate the useful moment
Open the editor, add your clip and play it once without making changes. Note where the action really begins and where it stops adding useful information. If the clip contains private material, check how the editor handles uploads before importing it.
2
Trim without cutting the meaning
Move the start and end points past dead air, camera setup or an awkward sign-off. Leave enough context for a viewer to understand what happens. Edit video in small passes: a conservative first cut is easier to correct than an aggressive one.
3
Preview, export and replay
Watch the entire trimmed sequence, including its first and last second. Select an available export setting, save the file and play that saved copy rather than trusting only the editor preview. Check that picture and sound both survived the export.