I m not expert in oc but i can tell you a little bit about my method
For Memory :
First i set XMP profile. Then i start to UP frequency and release timing to find Max frequency until Motherboard doesn't POST (BIOS not booting).
Once i have max frequency i start to tune timing at this frequency. I turn down CAS latency first by one increment at a time, if it POST, i turn down by one increment other timing. If it still POST then again i turn down CAS by one and so on.
This gives Max frequency at Min timing.
Then i turn command rate to 1T and with same method i try to find Max frequency and Min timing.
Once i have those information, i try to boot to windows and i use AIDA to test stability. If it's not, i release a bit timing. Then i compare perf i get from 1T and 2T and i choose the lowest latency over highest bandwith if bandwith gain are low.
For CPU :
Undervolting at stock (my way for SFF) :
It's not overclocking, you won't get higher frequency but lower powerconsumption, so less heat, so less noise and higher lifetime for your CPU.
I use offset for this. Wich means i let the CPU operate exactly the same way he is supposed to do : he adjust his voltage to every of it's possible frequency. But i set an offset to his voltage configuration to use less power.
So in BIOS i set offset to something like -0.1v. If it POST, i validate fast with 5min in Prime95 (Small FFT). Then i try to turn it a little down until it crash. Then i go up like 0.01v up until it didn't crash. I validate a bit more. If it work i still turn my offset a little up (0.01v) to take a margin. This way i never faced any instability.
You can use the offset method but it's a lot more tricky and you can't get every Mhz you can with static voltage.
So every tutorial use static voltage with LLC tuning.
First thing to do is minimize your Vdrop. Vdrop is the difference between the vcore you set and effectively get. It's were LLC is used, you up LLC until vdrop is minimal.
Then you can up frequency (by tuning Ratio Multiplier and BCLK, usualy BCLK can't go up very far) until you get instability. Once you have instability you up the Vcore and minimize Vdrop (LLC up). Check Heat when you up Vcore. Max temp i recommend is 90°C and max voltage is 1.4v.