Best CDP isolation device you use?

cheapest way, get from Chinese hard wooden chess. It is very cheap in Asia.

It gives you a more open soundstage, involving vocal and improvement in the mid and high.

The shortcoming is, bass will be slashed a bit.

I get it fairly cheap.......and find it very useful.

DH Cones and BDR cones I have found to make a cange in sound but never for the positive IMHO. The best bang fo rhe buck ise is Symposium Rollerblocks and or The Aurios versions. I have more experience with the Symposium products but I heard the Aurios stuff under my friends system and it made things sound much more cohesive but still more congested than my rollerblocks. The rollerblocks combined with a super plus or ultra shelf is the best I have heard to this date and I have expreimented with isolation products. The BDR cones are silly when compared to the Symposium products. Granted they are loads cheaper...
I have also heard excellent things about Walker Valid Points from ears I trust.

1/2" balls on top of 3 Aurios pros on top of Symposium ultra on a rack resting on more Aurios pros.

Resolution Audio Opus 21 sitting on 'large' DH cones (the smaller rubber feet on the cdp are junk). This sits on a Machina Dynamica Nimbus, which in turn, sits on a custom made Sound Anchor platform (w/spikes going through the carpet and a three-point contact on top).

I found the Clearaudio Magix to work very well. They are expensive, but when you consider they totally decouple the CDP via magnets from any floor/shelf born vibrations, it's probably worth it. You can also save money by not having to invest as heavily in specialty equipment racks or bases.