Content Marketing and SEO should go hand in hand.
Or well, in overall a correct Digital Marketing should take into consideration all the pieces of the puzzle.
After we have done our keyword research, developed de proper SEO content and have done the On-page SEO, the Off-page SEO also takes its importance.
A Backlink SEO Strategy should set up the categories of the sites that you are aiming to get backlinks from.
Also, take into consideration that this is a long term process, therefore your time period of this project should be measured in a long lapse of at least a year.
We have already talked about SMART Objectives, therefore set out your targets.
As example: Create 10 monthly backlinks from tech blogs that have a MOZ Domain Authority of 40 and Ahrefs Domain Rating minimum of 30 with a contextual backlink to the keyword best Smartphone Store in Spain.
Also, take into consideration that you should set a budget for sites or blogs that charge for posts.
There are even websites were this process is easier such as Getlinko, where you can buy backlinks in quality websites and can help you to reach your SEO goals.
There are other options such as Blogger Outreach or Cold Emails for Guest Posts, that could also help you to get backlinks, but it will require time to create the contact.
Avoid spammy backlinks in your Backlink SEO Strategy, there are plenty of websites or facebook groups were it is offered hundreds of backlinks, but most of them are low quality or just spam.