I was in the same place as you earlier this year. So I made a rule for myself.
If the link doesn't "seem" editorially given I avoid it and spend my time on something else. That pretty much rules out everything that is popular with the blackhats/greyhats including: ALL article directories, automated software, web2s, blog commenting, low quality link directories, low quality press releases, paid sitewides and footers, "guest posts" on low quality sites, keyword rich in-content links, forum signatures, profiles setup solely for the purpose of a link, etc.
I don't think avoiding these things makes me whitehat. I still buy links, use directories, press releases, guest posts, etc. I just am more smart and selective about it.