Make custom reports that show only natural search traffic, using a couple of basic custom filters.

If you have a PPC (pay-per-click) search effort happening, you may be allowing the PPC engines to loosely match your paid-for terms with various terms typed in by human searchers.

To keep abreast of what’s being matched to what (and maybe identify inappropriate matches that can be avoided by adding negative search terms, or get ideas for cheaper exact-match terms), try this report.