Every brand with an AM4 motherboard is included in all of our images of settings to alter. We have done this to include all overclockers.
Some motherboards require you to choose a mode on how to overclock. ASRock might also include CPU Voltage in multiple areas; you should only need to change it in one place. ASUS allows you to choose to overclock with D.O.C.P/XMP mode, which is how we do it on their motherboards. It automatically takes up your RAM to its profile settings and then allows you to set CPU ratio. On Biostar motherboards at the time we tested, you could not easily input a multiplier. Instead, you had to rely on core FID and DID values, and Core VID could be used to change the VCore.
On the Biostar motherboard you can increase FID and leave DID at 8, and you will see the greyed out frequency increase or decrease based on what you do. On the GIGABYTE board you see above we just change CPU clock ratio. MSI has a normal and expert mode, we just use expert mode, but you can also use it normally. Remember you can change the multiplier in 0.25x increments so that you can increase CPU frequency in 25Mhz steps. Default voltage when you overclock should be 1.3625v, and you can change it, but on many motherboards, I just use the 1.35v that comes with default VID. Coincidentally my nice 1800X likes 1.35v for 4GHz.
There two ways you might be able to increase your overclock if you reach a thermal or other limit. You can disable Simultaneous Multi-Threading (SMT) which will remove the two threads per core feature of the CPU. So if you disable SMT on a 1800x (8 cores 16 threads), you will get only eight cores with eight threads. You can also turn off cores, and that can be done through Downcore Control. The good news here is that all motherboard vendors have decided to call these settings the same thing.
Some motherboards allow users to access AMD's CBS menu. Inside the menu, the settings are standardized as this is part of AMD's core part of the UEFI. If you navigate to AMD CBS\Zen Common Options\Custom Core Pstates and you accept the warning, you can actually change individual core P states and FID, DID, and VID. You can see the resulting frequency and voltage. I believe that VID is in hexadecimal. I wouldn't overclock through this menu, but there has been a lot of discussions online about it.
The main voltage you need to change to overclock the CPU is the CPU Core voltage; most vendors call this VCore. Don't set this over 1.45v for 24/7 use, although cooling the CPU at that high of a voltage is pretty though. I like to stay below 1.4v. By default the CPU VCore should go to 1.3625 when you overclock, you might want to change the voltage manually, so you aren't over or undervolting the CPU. You also can change the CPU SoC voltage, and that should increase memory overclocking potential. Default SoC voltage is 0.99v, and AMD recommends no more than 1.2v. There are also other voltages you might need to change, for instance on most motherboards you need to increase DRAM voltage to what your sticks want.
Depending on your motherboard you might also have VRM/PWM settings that control the external VRM's PWM controller. These settings can be used to stabilize a fluctuating voltage and increase power limits. Load Line Calibration (LLC) is used to stabilize fluctuating voltage, switching frequency determines the aggressiveness of the VRM (higher is more aggressive but less efficient), and over current and voltage protects can be increased to maximize output. You typically don't need to touch any of these settings other than LLC. CPU SoC LLC is called VAXG on GIGABYTE boards and NB on MSI motherboards.
Some motherboards might have a more basic VRM, and on those motherboards, you might not have the ability to set the whole voltage and instead just an offset. The offset is an amount added to the base voltage of the CPU, so that should be between 1.35 and 1.3625 when you change the CPU multiplier. The SoC should be 0.99v by default so your offset can be added to that.