Personally as of recently, I have basically stopped changing a lot of kernel settings. I change the color calibrations, I tinker with a few things (I disable logging as an example), and I play with new stuff that has been added (schedulers, governors, or whatever it may be). But for the most part I just flash it and let it go. Quite a few kernels have SR enabled, which makes manually undervolting semi-pointless.
I know this isn't what you want to hear, and I would recommend settings, but each device can react differently to setups. By this I mean, if I tell you my overclocking and undervolting settings (if they were different than stock haha), and you were to apply them, your device may not like them. You could see problems in apps, device lockups, reboots, and unnecessary battery drain. Also perhaps my usage pattern doesn't require faster speeds, or "faster" governors, that yours you may notice some lag.
I find that experimentation is the best way to find out what settings are best for each device, setup, ROM, or whatever.
