Any Tips to maintain PBN blogs ?

Hello Everyone,

I have around 12 blogs on mens fashion / Hair style / spa Niche..

I'm looking to expand my online business.. So, I planned to add 20 more blogs..
Any tips & Tricks to Maintain Network of blogs ?

I post quality contents to blogs & of course Niche relevant contents..
No changes in Trust flow & Citation Flow..
Page authority & Domain Authority also same.. When will it gets Increased ?
What should i do to increase authority ?

Salutations,
Kim Jong-un