Installation process and ARB?

[Hexanol]

So last year I remember when I've decided that I wanna try MIUI EU ROM, opted for bootloader unlock, then I successfully unlocked it -> installed TWRP, and then decided that I'm gonna install MIUI EU ROM (it was MIUI 9 based back then). And guess I was able to brick my device and couldn't use the phone for like a month. (That ARB thing back then was pretty new and I remember that I've updated to 9.17 or something like that with ARB value 4)
Now I'm pissed off by those slow updates from Xiaomi for their Global devices and wanna try EU ROM again. But this time I don't want to brick my device again. My bootloader is unlocked, I'm on latest stable global 10.3.1.0 (PIE) - using the global version of the phone.
Could someone explain to me how to install the MIUI EU ROM? Explain like I'm five.
And can the ROM itself update via TWRP without any problems? I've never tried EU ROM so it's not so clear for me.

*Don't judge me for asking simple question where it probably got answered, that ARB thing was pretty unexpected and the struggle was real when I had bricked my phone. So I don't want same thing happening again*

 

[sfslesh]

Well..in my experience about custom miui ROMs,I can boot it only from default miui rom..for example if I'm on Havoc OS I can not successfuly boot Xeu rom..in order to boot it I have to roll back official MIUI..so after that boot into twrp..go wipe fallowing
Dalvik
Cache
Data
Vendor
Don't wipe system,internal,SD just those 4 lines
Then you install Xeu..magisk optional..before all this download Xeu rom for whyred beta or stable put it in SD or internal..that's how it works for me..cheers

Sent from my Redmi Note 5 using Tapatalk