There is the most used methods such Guest Postings, articles Posting, Images tags, ebooks...etc but since the new google updates.. the SEO become rough and Though.. so you will need to find the good method that work most for your website.. the most important now day is the content and Being Social...
Unique and quality content is the basic key then submit it directories but it gives more sense if you upload it to your website if not that guest blogging can help very well to.
In content marketing best method is unique and quality content use for articles. It is beneficial marketing achieve high level of visibility and increase traffic.
Guest posting is the ultimate way, i never see that kind of great source to promote our business..This is the standard and newest method in content marketing.