I haven't been able to find the original ABC bird tape online for a
while, but another option is to use window markers (like the "congrats
class of 2021!" on cars) and put the blue painters tape on the window to
make straight lines and simply paint the lines on.
There is also the "zen curtain" option. It's essentially para-chord
strings hanging down in front of the offending window. They blow
gracefully in the wind and create a visual barrier for the birds. I
think they look pretty cool. https://abcbirds.org/acopian-birdsavers/
Thanks for working to make your windows safe! I've always been told that
even if you have only seen a window strike causality once or twice,
there have likely been more that were scavenged before you saw them.
Better to be safe than sorry.