I would create habitats in which prey populations would thrive. Make your yards and nearby areas a little 'wilder' (but while maintaining a healthy relationship with your neighbours!) by creating brush piles, planing more native species.
There are lots of ideas and plans for owl nest structures.
Here are some links to building nest structures for owls ...
One of my favorites: https://www.amazon.ca/Woodworking-Wildlife-Homes-Birds-Animals/dp/0975433830
https://feltmagnet.com/crafts/screech-owl-house
https://www.barnowltrust.org.uk/barn-owl-nestbox/barn-owl-nestboxes/
https://www.pinterest.ca/pin/174796029271852720/?lp=true
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