Cheap tweaks...What would YOU reccomend?

Inner Tubes are a joke. Here are ones that do work.
1)Speaker placement. For example with a 12 X 12 room place the listening chair/couch 3' for rear with speaker 3' from side walls and 2 1/2 from rear. Use this formula and toe in 3 imches. It will work. Spike and and all speakers and subs.
2) subs sound better up front on one side or the other cross firing edge of woofer parallel with edge of front speaker
3) Do not put sub or speakers in a corner
4)soft pucks helps cd players and transports
5)get a dedicated audio stand -fill with play sand
6)let equipment warm up stabilize before listening at least 30 minutes

Get rid of your wife...

By far, the best isolation devices I've ever experienced are simple fiber scratch pads. They come in varying thickness and stiffness. They are almost 100% immune to vibration. I say "almost" because nothing is perfect. But when you put your hand on the component they're under, there's no detectable vibration whatsoever. They seem to be acoustically dead. They are awesome under a turntable.

Here's a really cheap idea...Stop worrying about tweaks and listen to some music.

OK I just finished reading all the tweaks listed here and would like you to consider the cheapest and best tweak I can think of. It is often used in the boating circles that some
people find are real money savers. My brother in fact did this with his boat and although he is not known to be the brightest bulb in the room it does seem to make a lot of sense. He sold his boat and now goes out in his cousins boat. We can do something similar, short of selling all out gear.
You simply do some research and find a few audiophiles in your area that are known to have really great sounding systems. Shoot them an email or phone call and arrange for a hookup. You can even invite them to your place for a listen to your rig. you can make new friends and enjoy listening to their systems they they have invested thousands of dollars in and untold hours of tweaks. You can save enough money dong this to even afford a few nice bottles of wine to share with your new audiophile friends.