Quick fixes
 

Yesterday, just because it was a nice day for the first time in months, I couldn't resist the urge to fiddle with my car. Just for the hell of it, I cleaned the ICV, since I've heard of people doing that. Made a huge difference! Idles much lower when hot (it was idling at about 1100-1200 hot in P and N, now about 700-750), smoother transmission engagement too.

So here's my question: Are there any other either really cheap or free quick fixes or improvements you can do like this to make a difference? Anything else to clean gunk out of?

You fixed one problem, good for you.
Don't fix anything that ai'nt broke !
Sometimes idle hands can get you in a lot of trouble. ;)

I did my own t-chain in addition to many other things on my car, and the t-chain on my aunt's 126. I'm not claiming to be anywhere near the level of many members of this board, but I can handle myself. No words of wisdom necessary. ;)