Your most indispensable "tweak"?

redwoodaudio
There is a big thread on them here in the forum. They simple made the sound so much cleaner sounding across the board. Back around vocals where much stronger, able to see deep into the sound stage. More black space around the sound. 

Here is a few.
1. Sorcer X4
2. Critical Mass Footers under components
3. Iso Acoustics GAI 1 under speakers.
4. Stillpoints Aperture 2's

No one's going to say "divorce"?

Deoxit.

Bybees by a country mile