Hi in my opinion most effective Quality content and choose a perfect category because when ever i have posting a link in submission sites so at that moment i have with out select a category submit that so my opinion create a quality content and informative details.
The activities remain the same but just avoid spamming. The main change in OFF page activity has to be using diverse link anchor texts, it was evident that Penguin 2.1 has hit hard for the ones who have been using exact domain anchor texts. Vary your anchor texts and keep exact domain anchor texts at minimum, use long tail targeted keywords as anchors, stop spamming in blogs & forums. hope this helps.