If I am dealing with a slope, I tend to plant daylilies, which are beautiful in their own right, have nice foliage and do a smashing job of holding the soil together. If I am dealing with what is simply a huge expanse of yawn-inducing green, I plant shrubs. Shrubs come in an infinite variety of colors and textures. Some flower, some provide winter color, and may provide berries that help the birds through the winter. And then I tuck flowers and groundcovers around those.
Hellebores love light shade and pop into flower even before the daffodils have made an appearance.
Long before the lawn turns from dead buff to green. So far I've managed to do away with about half an acres worth of grass this way, which leaves my husband time for more important things like building me a greenhouse. If I want that done by winter, though, I'll have to resort to more drastic measures, like planting a meadow that doesn't need mowing at all. If you want to create beds but aren't sure how to make a workable design, Design0 will get you started. Here are some good tips for creating a landscape full of color.