get warm sounding speakers or components.
tube equipment usually has a degree of warmth.
Buy some good all copper interconnects and speaker cables.
I would not expect a power cord to add any significant amount of warmth to the sound. At least I've not seen one that does. In my experience, power cords that appear warm at first usually take away some good things, like dynamics, transparency, detail. You only realize it later when you get used to the change.