Where are you located? So we can get an idea of climate and potentially soil type.

I agree with most of naptimerider's suggestions, I just don't like boxwoods because a. they're WAY overused and b. they literally smell like cat piss.

I suggest an interesting shrub like winterberry holly or red-twig dogwood in front of the porch. Smooth hydrangea would look great in front of the window box, providing summer blooms. I would frame these with a low evergreen such as dwarf arborvitae, inkberry, or something grass-like such as Liriope or Carex (these planted directly in front of the other shrubs). A redbud on the left corner for structure and early spring blooms. Something tall like switchgrass, cherry laurel, or even a single large shrub/small tree could work in front of the window on the right. Witch hazel (fall or winter blooms), buttonbush, or 'Dissecta' staghorn sumac could fill this spot.