North Carolina is zones 6 and 7, much like our area so their native plant advice is always good to check. NC has a much more active Extension service for home gardeners and as a result they post many more advice and plant-specific articles of interest.
You'll find their 4-step Go Native planning site here, complete with how to think about the process and plant guides.
Another resource we can use is the Missouri Botanical Garden's link called Selected Perennials for Oklahoma Gardens.
Oklahoma Garden Clubs posted an assortment of native plants for home gardens on their website, too. Their selections are primarily ornamental grasses.
The OK panhandle, Oklahoma City, Southeast, south central and northeast OK all have different soil, annual rainfall and temperatures so do some more research for your specific climate when deciding what to plant.
Internet research really helps, too.
From a 2010 entry of Grounded Design by Thomas Rainer in his Landscape of Meaning blog
Ten Bold Native Plants to Update Granny's Cottage Garden
NATIVE PLANTS FOR THE COTTAGE GARDEN:
1. Wild Indigo (Baptisia australis): The colorful spires of Wild Indigo have much of the romantic effect that Foxgloves or Hollyhocks had in the English cottage garden. Used in the back of the border, Wild Indigo doubles as both a filler plant (when not in bloom) and a structural plant (when in bloom). The plant also fixes nitrogen in the soil, actually improves the fertility of your planting beds. If you like yellow in the garden, the cultivar ‘Carolina Moonlight’ is spectacular.
Nothing says grandmother’s garden like the billowing blooms of garden phlox. This sweet, upright perennial reaches 3-4 feet tall, and blooms in late summer when many other perennials are spent. Great for butterflies or hummingbirds. Try some of the newer mildew-resistant cultivars like ‘David’ or ‘Katherine’.
The great William Robinson called Goatsbeard “perhaps the finest plant for the wild garden,” and I would have to agree. This edge-of-the-woods native can handle light shade or full sun if kept moist (if you live in the deep South, keep it in the shade). In early June, the tangle of raspberry-like foliage erupts into stately cream-colored plumes. Allan Armitage claims that the males are more sought after than the females because they produce fuller blooms, but either is great in the garden. When it's happy, it can grow as tall as five feet, but it's usually closer to three to four feet tall. No fence line is complete without this versatile forb.
7. Swamp Rose (Rosa palustris): I fell in love with this plant while wading through the swamps of the Eastern Shore of Maryland. The blackgum swamps were about the last place in the world I expected to see a rose, not to mention one as showy as this one is in June. But there it was, loaded with single pink flowers that attracted a cloud of native bees. The graceful, arching habit of the shrub was as appealing as the blooms, and bright orange rose hips and brilliant red fall color are some of the other advantages this rose has over it's exotic counterparts. If you've had trouble raising roses because of damp soil, this plant is your answer.
8. Culver's Root (Veronicastrum virginicum): This perennial is a flat-out show stopper, dispelling the myth that native plants are not as showy as their exotic counterparts. Culver's Root looks like a Veronica on steroids. Slender white spikes that look like a candelbra crown strikingly upright stems. It blooms for up to eight weeks in mid-July and will last as long as ten days in a vase. This plant is highly effective in the back of the border where it can be mixed with taller shrubs and grasses. Plant in clumps of seven or more for a truly dramatic effect. Culver's Root loves moist soil but will tolerate some drought once it is established. Newer cultivars like the lavender-colored 'Fascination' and pinky lilac 'Apollo' will make you wonder why you ever even bothered with Foxgloves.
9. Wavy Hair Grass (Deschampsia flexuosa): Every cottage garden needs grasses. I don't care how smitten you are with blooms, you must make room in those beds for light catching grasses like Wavy Hair Grass. Low grasses like these are essential in giving small gardens that expansive effect, recalling larger rural landscapes like meadows or pastures. This particular grass is a delightful and elegant native that thrives in full hot sun or dry shade. It can even withstand the heat and humidity of the mid-Atlantic and deep South unlike its better known cousin Deschampsia caespitosa. In spring it is topped with feathery inflorescences that capture and hold light and sway sleepily in the breeze. Incredibly tough and attractive year-round.