Did this once, then the site went down! grrr
So, you have the ferns, so many wonderful leaves and colours to choose from. Then any of the woodland plants. I have a couple of dicentra that thrive and look stunning in the deep shade of my willow tree. Then there are astilbes, foxgloves, primulas and so on. I guess watering woul be the main issue with any of these plants. Oh, and bulbs, if it is seasonal shade, then spring bulbs who do their thing before the canopy is thick would look great!