Guys which is the best way to grind for the proper enhancements that I'm seeing some people recommending in some guides regardin the meta, because I have all the set bonus gear pieces on me,irating 306 but my stats are all screwed up !!! XD

Play the game, whatever parts you normally do. Drops (and renown crates) can include good enhancements themselves or gear pieces that have good enhancements in them (*)

 

People do run VM and MM Hammer Station repeatedly as well for gear drops.

 

(*) Pulling these enhancements is expensive - credits wise - but is less expensive than other methods of acquiring them.