I have a small area in the corner of the yard (8 X 8, or 10' if I want)
I have picked up my plants but haven't put them in yet. My only "height-plants" are grasses, Karl Foerster and a couple variegated reed grass, blue oat grass for infront of them. Then I have a couple bee balm , 3 coral bells, 2 blanket flower, 2 dwarf winged Euonymous and then for the front... 5 silver mound.
Last night I picked up some salvia and verbena to fill in some spots. Phew...that was a mouthful Any thoughts on how to add more height in the back? Thanks!

Hollyhocks, Joe Pye Weed, Rose Mallow, Lucifer Montbretia, Maximillian Sunflower, Trumpet Lilies, Indian Cup, Tall Coreopsis, Canna Lillies....just to name a few.

Oooh, 'love canna lilies. Hollyhock would attract more butterflies and hummingbird too????

My Bee balm gets over 3 feet tall. Theres some height.

What about an unplant item. An old chair, an unused gate, a statue, an oblisk, a pole for a flag or bird house. Just a few ideas.
You can find a lot of things just sitting around. Or in the basement or attic. Just let your imagination go wild. I once saw a baby crib head board in a garden with a plant climbing around it. I'm going to try that. The crib myself and siblings slept in is now not safe.(slats are too far apart, funny 6+ kids slept in it but is now not safe)