sparingly

adverb1

1. •
   In a sparing manner; with frugality, moderation, scantiness, reserve, forbearance, or the like; sparsely.

   • The Mark Tree is generally used as an effect to accentuate transitions in music, either at the beginning or end of a phrase. When used sparingly, they ^([sic]) can add an exotic "shimmer" effect. — 2008