I would say the first step would be to upgrade what's behind the wall. Like in plumbing, you start with bigger pipes and you go down in size when you reach your fixture. So if you use a bigger gauge power chord and the wire behind the wall is a smaller gauge you won't get the full potential of the power chord.
Power Cords - Just Say Yes
I'm the biggest cable skeptic on the planet. I've never been able to tell the difference between one speaker cable over the other. I've never a/b tested because I just can't handle that sort of thing when all I want to do is listen to music. The power cord however is a whole different beast. I know. I just replaced a 18/3 that was powering my Rogue Cronus Magnum for two years with an Audioquest NRG4. I know some people aren't fans of AQ but that's what my local guy sells and I support him 100%. He sold me a broken in demo which is exactly what I wanted. I didn't do an a/b test and I didn't have to. I pulled the old one out and tossed it in the copper recycling pile and replaced it with the AQ. I fired up my amp this morning and let her warm up. I pulled out Sylvain Luc & Bireli Agrene's 'Duet' and hit the play button on the remote. Right off the bat I had to blink my eyes to make sure I was actually in my house. Everything tightened up with a dead silent background. I feel like a fool for waiting so long to come around on this one. I'm still skeptical of whether or not I will notice a difference when I replace the power cord to my CDP, but if you tell me I'll notice I might believe you. Either way, that's my next investment.