Not a designer, but have planted a few plants in my lifetime to good effect. It all depends on where you will place this plant (corner, nook next to stairs, etc), the style of your house, the color of your house, other plantings in place, and the eventual height and width you want to target. A picture is always helpful. I see that you are in zone 7 of Maryland. I can throw out some general suggestions based on the zone you live in and the assumption that this is full sun: Foster holly/hybrids (if you like chartruese, try Ilex x attentuata 'Sunny'. A stunning plant all year round and can be kept to a reasonable size by pruning, which also keeps the chartruese new foliage coming.), Juniperus 'Sky Rocket', any number of Chamaecyparis, Thuga 'Emerald Spire'. The list can go on and on. It all depends on what you need.

I am curious if you are expanding the front narrow beds to include shrubs. Where I grow peonies, daylilies, and iris, I also grow strawflower, dianthus, abelia, and lambs ear. What about a Soft Touch holly, or a native holly? There are some very low growing crepe myrtles now, but that's my zone 7 talking. If you're open to daisy/echinacea/rudbeckia type coneflowers, a little planning can make sure someone is always in flower. PowWow White is off patent now so you can propagate your own. You can totally plant the whole thing in white veronica and salvia, that sounds adorable. I'd add liatris alba and an artemisia too.

Wow, that's a lovely classic style! Congratulations on your new home. Which corner of New England are you located in? Coastal Connecticut 's climate is quite different from northern New Hampshire ;) I wish you had a poured concrete sidewalk to make snow shoveling easier; maybe that will come in a future upgrade.

I'd put a mix of low-growing flowering perennials under the Japanese Maple. Pink coreopsis, phlox subulata, veronica spicata, and salvias. Pick a mix of flowering times, so you have blooms all summer. What's in the bed to the left? No to tall plants flanking the entrance. Note that your two beds on either side of the walkway are not quite the same size. I'm fond of broadlead evergreens --- rhodos and azaleas. It looks like you have some yews to the left. If you are going to remove them, I'd plant the best ones on either side of your driveway near the road.