scp uses sftp protocol by default since v8.8. You'll need to pass `-O` parameter to explicitly use the legacy scp protocol if you still need it for backward compatibility reason.
I like how this guide also takes Windows into account, it has some unique challenges.
I have written some notes especially on SSHFS (also for Windows!) and tunnels with SSH (e.g. SOCKS proxy) as an OrgPage: https://www.orgpad.com/s/wRIx3rNLZ6y
These tricks saved my bacon so many times already. Most of it can be used with the FUDO PAM jump host appliance (https://fudosecurity.com/fudo-pam/) that is based on FreeBSD and one of the developers spoke about it and other things on https://www.bsdnow.tv/ I think. Some of it works with OpenWRT's Dropbear nicely as well.
This is a nifty trick, but I recently had an issue where it would offer my other keys even with IdentitiesOnly yes specified in ~/.ssh/config. I found a solution [1], but it's not the most elegant.
The most annoying "feature" of ssh for me is the discrepancy between public keys presentations. How I suppose to verify fingerprint of a new server if it uses a different presentation in the keys file?