Need guidance on isolation devices

I'm looking at venturing into isolation devices for my stereo. I have none, and I've been reading quite a bit, but as usual when I first get into these matters I'm somewhat confused and would appreciate guidance from experienced users.

My system is not the highest resolution, and is in transition: Rotel CD player, Rotel preamp, McIntosh MC275 (tubes). The system is in front of the speakers, about 10 feet away.

I'm thinking of building isolation platforms sitting on air (bike tubes), and sand-filled boxes. Been reading about these, about tiptoes, and about heavy weights on devices such as cdps.

Which of the above, or combinations, are better suited for each component I own?

On which component should I focus first? Where would you expect me to perceive the largest improvement in sound?

Thanks in advance!