Take three plant species. A spring blooming small tree - crabapple, a deciduous and evergreen shrub - Hydrangea paniculata and Ilex x meserveae, the Blue Holly. Plant them in front of, among and behind the trees. Plant them for screening the sight lines you want to cover and consideration of their sun needs in the quantities needed.

Maintain the ground of this buffer as a meadow with whatever comes up. Just give the trees and shrubs some elbow room if needed while they get big enough to fend for themselves. You can add more meadow plants later once you know the mowing schedule that suits you best. Once a year works fine for me.

This is where your leaves can go for the winter. That and the shade will determine what kind of meadow you get.