Link building can be a very cost efficient way of doing marketing on the internet, if it is done right. The most important is to make a strategy that keeps you focus on using the most efficient link building methods.
I have made this article to give myself a shortlist to look at when I make a link building strategy. I hope you can use it as well 
Please check for updates in the future.
Name: Directories
Short description: Organized list of web sites by categories.
Direct and targeted traffic: Directories can bring targeted traffic, especially from big and specialized directories.
Value for search engines: You get the biggest value from directories that have a personal evaluation, a high page rank and that are specific for your category. The lowest value is from automated directories that might be considered as “link farms”.
Time requirement: Low
Other: Remember to focus on bringing costumers to your web site from the directories and not only to get a link juice from the directories.
How to do it: Find a list of the biggest directories. Within the directories, search for more specific directories in your category. Make a cost/benefit assessment to find the directories worth the effort. There are many companies specializing in submitting to directories; a few deliver good quality and good value. With your final list of worthy directories you start submitting.