You have good ideas already. Some others that come to mind, for native trees and shrubs that support wildlife: juneberry, chokeberry, hawthorn, hazelnut.
Habitat additions may include:
ringing the bottom of the bed with stones (or including a little pile of them somewhere, if fully surrounding the bed isn’t an option)
laying a terra cotta pot on its side in the soil, facing north/east or on the shady side of the bed, great
reuse for a cracked one
placing a dish of small stones and adding water daily (I use a huge terra cotta saucer for this, catching water under my spigot)
leaving small log or board on the ground to rot
These things are helpful for many animals, but in my garden I’m thinking mainly of toads and salamanders when I do these things. Oh a little brush pile is great, too - cover for small animals like snakes, and maybe home to beneficial insects.