A good PBN gets its power (& worth) primarily from good auction domains,
Domains that should be clean, and have a good link profile, so that they would pass a decent amount of link juice,
Many people will mess up getting the right domains,
Because of the disturbed misinformation, like entirely relying on "DA", "DR", "SS", and other useless metrics,
You can use these to filter the lists initially, but you'll have to know how to select each of the domains carefully, and bid with the right price for each,
Or you can rely on some trusted sellers that would do the work, I can personally vouch
@Nargil for this,
The rest will be about the PBN on-page, where you have to #1 avoid leaving any footprints (or as less as possible),
And #2 to make sure each of the websites looks genuine, with decent content & design, drip-feeding content, adding "important" pages, SILO, internal linking, etc...
If you want a solid PBN that would last for the long term and won't get your website(s) doomed, you have to treat each pretty much as a money site,
A good PBN could be considered as an asset, so you can sell/rent or re-use it later, so the more careful and the better you invest in domains, the better
