Open up setcpu, click the tab up top VOL TAG, and start tinkering. I'd advise you to follow some sort of starting point/guide so you don't go frozen and have to battery pull
Also DO NOT check the "set on boot" option until you've thoroughly tested your tweaks for a couple of days. Just remember when/if you reboot at anytime during your testing to go back into setcpu and change the VOL TAG values. Once you're golden you can select the "set on boot" and you won't have to fool with it again.
I'll come right back and edit this post with some starting point values for you
EDIT: as of #10 I see franco suggests leaving everything at default as UV is built into the kernel. Matter of fact UV might be disabled in #10 I haven't tried it yet. If it is available you could tweak down the mV's if you wanted to tinker. I'd suggest trying 25-50mV tweaks at a time play with for an hour, run a stress test, whatever and see if you get a "sleep of death" aka screen not coming back on or a random freeze. When you run into an issue bump the voltage back up 25mV's and test again to make sure. It's tedious, but fun too!
Here are the default stock kernel mV's so you know where they started at:
1200MHZ = 1380mV
920MHz = 1317mV
700MHz = 1203mV
350MHz = 1025mV
Values I used safely with #7.1
1200MHz = 1175mV
920MHz = 1050mV
700MHz = 975mV
350MHz = 850mV
Taken from franco:
SetCPU profiles not at all, they only hurt the device's performance/battery. Everything that is needed for top performance/battery it's already set by default (in my point of view of course).