I've spent 2 years preparing the soil and last week I finally got to plant! I took all the wildflower seeds and mixed them up in the garden cart with a mixture of peat, perlite and the dregs of potting soil bags, moistened well and stirred thoroughly. I broadcast the seeds by hand and then overseeded with three kinds of native grasses.
Prairie dropseed (Sporobolus heterolepsis) went along one edge. It was the most expensive and makes fairly low growing mounds so I wanted to show it off.
Side oats grama (Bouteloua curtipendula) is the tallest so went in a patch at the back as viewed from the house.
Little bluestem (Schizachyrium scoparium) covered the rest of the bed.
I've read that most of these plants will spend their first year growing deep roots and that it won't look like much above the soil surface. I will post photos as things sprout.