Many of the plants that thrive in shady conditions tend to be low growing such as hostas, heucheras and lungwort. If these are the only plants that you grow in shade then the area will lack contrast so the article quoted below suggests that you should include several taller plants to give a better impression. This article by Meghan Shinn which I found on the Horticulture Magazine website lists a number of upright perennials and shrubs suitable for shade.
If your shade garden includes a lot of hostas, heucheras, azaleas, Siberian bugloss, lungwort and astrantia, as many shade gardens do, you may notice that it has an overload of mounded shapes. Adding several upright shade plants among your mounding plants will create contrast and a little excitement. Here are some vertical plants for shade:
Upright shade plants for deep shade
Variegated Solomon?s seal (P. odoratum var. pluriflorum ?Variegatum?
Gladwyn iris (Iris foetidissima)
Ostrich fern (Matteuccia struthiopteris)
Western sword fern (Polystichum munitum)
See more at Horticulture Magazine