Your most indispensable "tweak"?

My most expensive tweak was also the tweak that made the biggest positive impact. The $400 that I spent on two sets of Iso Acoustic Gaia III Isolators for my speakers was worth every penny.

"PPT" stands for Perfect Path Technologies. Their products are currently not available and I'm not aware of any recent news regarding if the company is coming back. Last year there were many threads on Audiogon regarding their products; so, there is plenty of info available here if you are not familiar with their products.   

@facten

Annual ear wax removal

I was going to say that too -- hahahahahahaha

Yeah, there's been some good humor vibes in this thread. 

The Townshend Podium for my speakers have been well worth it.  

My $49 Bosch laser measuring tool.  Another AGonger mentioned it (thanks).  Fastest way to get your speakers to "disappear". Check distances, seating position, aim for sure but toe in and tilt too.  An inch matters.  Really.  

Cabling you can afford but not crazy.  

Been said before, ear protection for all loud activities. This is a life time hobby.