I think we should not avoid plot armor, but well some type of plot armor should be avoided according to your own taste. As for me, the plot armor should be logical and that's it. The kind of plot armor I will avoid is nakama plot armor....
Hardest: Writing battle scenes and how do I make another next battle keep interesting?
Heaviest: Writing tragedy for tearjerker, which I think somehow pulled it off
Easiest: Writing nonsense, no cap.
Lightest: Writing slice of life~