It think guest blogging on real and relevant sites is a good practice. Also, try to get links and social citations from relevant communities in your niche. I think the key thing now with link development is to really invest in content to build up your linkable assets, so you can share that content across other platforms and communities for links. Also, check out what your competitors that are creeping up are doing...have hey beefed up their onpage or are they just pumping a bunch of anchor text links to their site in an obvious and non-tactful way?
I think that the key thing now is to invest more in good content than you have in the past and to invest into the work that goes into promoting it...on the other side of the coin, there are a couple easy wins for if you already have content assets, such as doing reverse image searches for your images and seeing if anyone ripped them and asking for link citations for image that they borrowed....etc..
"...using this: sages act out of constructs but they do not rely on them"