Create micro site and embed a few keyword specific backlinks to your primary website in the content
Make a small, single-page "micro site" with content about any topic you want.
A microsite is a streamlined website based around a singular topic. While your website may cover an entire industry, a microsite is designed to build authority, rebrand a product or service, and make you a "thought leader" around a specific concept. The goal of a microsite is to build authoritative backlinks on a new domain, increasing your page authority and, eventually, your organic search rankings.
Now I am not talking about creating a blog and then just posting a bunch of backlinks to your primary website. That is a great way to get your new blog locked and/or deleted for spamming.
I am talking about creating a "microsite" featuring quality content in the same niche as your primary website. By doing this you can create your own authority site and use it to embed a few (2 or 3 per post) keyword specific backlinks to your primary website in the content.
These blogging platforms are very popular, and as a result they get crawled frequently by Google and other search engines. In fact, I have had posts on external blogs show up in search results before the web pages they link to on my primary website did.
The main thing that you have to consider when doing this is duplicate content. If you have an internal blog on your website (you definitely should), you will want to create different original content for your external blogs. You will also want to vary the keywords that you are using in your backlinks.
Another thing you will want to be sure of is keeping the microsite anonymous. Register it with a different email address, and be sure not to link to it from your primary website. Basically you do not want the microsite to be associated at all with your primary website.
Once you have your microsite built, you can post backlinks to it, just like you would your primary website. This will help it gain a higher page rank, and any link juice you gain will get passed on to your primary website. The best part is the microsite will act as a firewall against Google penalties.
Let's say you post to many keyword specific backlinks to your microsite. The worst that will happen is it will drop in Google's rankings. While this is not good, it is much better than having your primary website get dropped.
Another big plus for this strategy is you can repeat it as many times as you want. Just continue to build new authority microsites in your chosen niche, and use them to post backlinks to your primary website. The only limiting factor is your time and effort.