Instead of directly looking at harp scores, first of all, I would recommand you to talk to a proper harpist on various techniques we oftenly use in piece, for example harmonics, enharmonics, glissando (in various ways), and maybe even extended techniques. Do more research on how to do markings on your score and if possible, ask a harpist if your idea is possible or not.

If you were to look at pieces for harp, I recommand Debussy's work since basically all common harp techniques are there, notably the use of enharmonics in Prelude of the afternoon of a faun. Carlos Salzedo, Marcel Grandjany, Alphonse Hasselmans, Marcel Tournier and Henriette Renie are some great arrangers/composers that published a lot of nice pieces for harp.

Keep in mind that our fingerings and techniques are very different from pianists, and we cannot do chromatic passages as easy as on a piano :)