Im definitely stealing some tricks from this list, very useful!
Also, this Cierge thing is great! Didn't even know something like that exists (in asp.net core, except IdentityServer, which more like enterprise solution)
Just spent the last 2 months of my life implementing IS4. So far its really powerful and flexible. I haven't done much research on Cierge but it looks like a neat out of the box solution for people who need a quick and easy solution for SSO.