What you think is the best ? Mixed link building from : Articles,Blogs,Directories,Forums,Social Bookmarking etc or from Directories etc alone ?
Although I'm a big fan when you submit URL to web directories, I think the mix is a better long term strategy for earning money online. This is JMO of course.
The more the better. Mixed strategies tend to produce more links, and it is more likely that some of them will be high quality links, too.
Its like saying how should a new directory should collect backlinks? Every backlinks got different parameters. You should try to make it look natural, to Google. Like getting tons of directory link by one Directory, Social Bookmarking or any submission wont work. Its better to keep a rythm of 10-40 Links/day and being with it for a long time. That way, Google doesnt gets a alert on you and it seems natural and effective link building.