Here’s some things you may want to do to make sure you don’t leave yourself hanging in the breeze when things go SNAFU.

Before I make any changes I always save a copy of the running config to flash. In case you accidently delete the config, it gets blown away, whatever. I prefer to keep it on flash for quick restoration as well as viewing encrypted keys in plain text.

Routers & Switches
copy running-config flash:LastKnownGood

PIX & ASA
copy running-config flash:

Source filename [running-config]? 

Destination filename [running-config]? LastKnownGood

%Warning:There is a file already existing with this name 
Do you want to over write? [confirm]

Hopefully you already know this one. You can have the router reload at a specific time or in X hours/minutes. This is very useful when you’re ready to make a change and you’re not 100% you’ll break something or get locked out (like configuring AAA).

Reload the router in 5 minutes
reload in 5

Reload the router at 11:00PM
reload at 23:00

Cancel the reload
reload cancel

That’s all I can remember now, but check back and I’ll add more as I work on stuff.