Match the cut to the bloom. Plants that flower in spring or early summer set those buds the previous year on old wood — prune them right after they flower, or you cut off next year's blooms (azalea, rhododendron, camellia, viburnum, bigleaf & oakleaf hydrangea, sweetshrub). Plants that flower from midsummer on, on the current season's growth, are pruned in late winter while dormant (beautyberry, summersweet, buttonbush, smooth/Annabelle hydrangea, muscadine).
Don't bleed the trees. Maple, river birch and yellowwood bleed sap heavily if cut in late winter — prune those in summer. Oaks get pruned only in winter (oak wilt).
Everything else in the catalog — the forbs, ferns, sedges, grasses and bulbs — isn't pruned. Most perennials & grasses just get cut to the ground in late winter; many gardeners leave them standing through winter for the birds first.
Check-marks remember what you've finished this year in this browser, and reset each January. Dates suit the Piedmont — shift a couple weeks later in the mountains, earlier on the coast.