configuring ssh in Ubuntu

There are several things which one can change after installing ubuntu and using SSH. Here are some of the things which I would do, along with their descriptions (in red):

Sample changes in ssh_config file (found at /etc/ssh):

ForwardX11 yes    Forward X11 display

ForwardX11Trusted yes   Forward X11 display only from trusted sources

ServerAliveInterval 5    Send small packets of data every 5 seconds so that SSH connection does not time out