I don't have much SP and since I mostly publish in a somewhat narrow (and not necessarily broadly popular) niche — spirituality and self-development — it can be hard to be see and build much.

What little I can offer (currently 2-3 cents a vote) I tend to give to content that is somehow helpful, interesting and worthwhile to me, and that I think might be the same to others. And I try to engage and interact as much as possible where I do visit; show the poster a little gratitude for their efforts.