Don't fully write off your 'traditional' methods yet, yes invest more time into content marketing but find a balance between the two.
The directory, social, article, commenting all still 'work' but you just need to be a bit more strict with the websites you chose to do this with (make sure they are 'good' quality sites) and if you are commenting or submitting a piece to them make sure it is of good value to their audience, isn't nonsensical and non duplicated.
That's my opinion anyway and no-one yet has convinced me that doing the 'traditional' methods of link building don't have any benefit any more or will penalise you if you take a professional and common sense approach.