Keep forgetting how to…

1. Use e.g. PuTTYgen to generate a key.
   Note: Fill out “Key comment” unless you want a rather messy, uninformative authorized_keys file…

2. Add public key on server:
   mkdir -pm 700 ~/.ssh
   vim ~/.ssh/authorized_keys
   chmod 600 ~/.ssh/authorized_keys

Should then work as long as the private key is then added to Pageant, WinSCP config, etc, etc.