I'm guessing most don't know about the /writeconfig cvar, judging from all the questions I see people asking. I use /writeconfig to save new settings any time I try them out and find I like them. (e.g., /writeconfig cfgname.cfg, hit enter, it writes everything).

Another useful thing to do is to create a directory (let's say it's called "settings") and store different cfgs in it with different settings you like. Maybe for different gametypes (like freeze.cfg, ffa.cfg, or lq.cfg and hq.cfg for low vs. high quality graphic settings). If you forget the name of the cfg you want to exec for those settings just type /dir settings *.cfg and hit enter. It'll give you a list of all the cfgs you have stored in there.

So be sure to name your config files in a way that you can easily remember what each one is. Um. That's all I got right now, I'm half asleep still.