I settled on a very simple approach to window management: workspaces. My sway setup has 20 workspaces on the main monitor and 10 for each other monitor. Most workspaces are dedicated to just a single window, some have more as is their purpose.
I'm curious how you switch between workspaces. Do you give them names? I currently keep a mental list of what each workspace is for, but I still use the standard numbers 0-9.