After Google updates this year many SEO
techniques are outdated. Between them is directory submitting. It doesn't mean that they don't work but they are not efficient as they was.
You should also count that Google will change algorithm even further in the future.
Try writing quality content and than share it on Facebook, Twitter and so on... I think Google loves this social networks more after latest algorithm updates and will love even more in the future. Just don't spam cause you may get in trouble
You may also do guest posting - writing blog post for someone else with link back to your site
Also in your article ask people to comment and share because Google loves that