If you’re in an area with a lot of deer, they love Tiger lilies and hostas. Daffodils are fool-proof and great in huge masses(see my field below house. This is happening now in zone 4 in NYS).
Hostas require shade and look best in large groups; iris are gorgeous and bloom in June with the peonies and early roses; black-eyed-susans run rampant in the sun.
You can plant a few poles or tall sticks and grow clematis if you fasten the vines to the supports.
There is also the interesting issue of when things bloom; you want color, fragrance and blossoms for spring, summer and fall, and if possible, interesting bark, evergreens and shapes for winter.
Bee balm, phlox, and mallow are fool-proof for summer.