Overclocking on the Intel Z270 platform is pretty easy. The easiest way to overclock would be up simply change the frequency divider in the BIOS. To achieve the best overclock we try to stay with the timings that the XMP profile recommends, but we will loosen or tighten timings depending on how things go.
The XMP profile puts this kit at 3000 MHz. In the BIOS I started moving up the frequency divider. I ended up with a stable overclock of 3200 MHz at the exact same XMP timings and voltage, so 3200 MHz with timings of 16-15-15-35 at 1.35V.
I did try to go past 3200 MHz, but we had to loosen timings so the overclock as not as efficient.