Im sure we all know that google devalued LOT of directories many years ago BUT I can assure you that there are a LOT of them that have pr 4 -5 and 6's that do pass page rank and can move you quickly cuz they get spidered several times a day. We've built a nice list of them for internal use. Granted most of them have free submissions and of course those take forever but almost all have some kind of paid review that can get you in quick and well worth the money. You just have to look for things the ones that actually review their submissions, keep their links relevant to specific categories and dont look spammy I only mention it because it can give quick listings, it will increase your PR and some will even generate traffic. Its easy and a better strategy for a new site than begging for links, forum posting, blog commenting etc. You should do that to as you want all the good links you can get but finding those directory gems can make your life better fast! There is a lot of opportunity at the moment in mobile friendly directories. it's easy setting up your site to be mobile friendly and most of the new mobile directrories are desperate for content and usually that is all it takes.
Directory submission is one of the best methods. You can use our PR4 directory. It's free for regular link submission (limited time offer) : explainervideodirectory .com If you're looking for a serious good backlink, submit a featured link
Syndication is key , which typically means Yes, content. I think it's easiest / best to start with free resources such as article directories, free directories, web 2.0 backlinks, social bookmarking, then as you understand the value, scale more to paid guest posting, blogrolls, etc.
As we need multiple methods of link building so we have to include all the methods for better result and natural links.