1. Do not do without paid advertising
Objections about the lack of a budget for advertising are not accepted. Because how you invest if not money, then your own time. And practice shows that the launch of advertising is much cheaper than independent promotion.

Let's take an example. You want to promote a new post on Facebook. To do this, you can:

a) set up and run ads

b) find independently thematic communities, compose posts, agree with the administrators on publications

c) find active discussions, subtract, compare opinions with ideas set forth in the publication, compile relevant answers and track comments

How much time will you spend on setting up an advertisement, and how much - on executing one of the remaining items?

There is no free content promotion: you either pay in money or in time.

In economics, this is called the price of choice:

the price of choice is the loss of profit when choosing one of the alternatives and the rejection of other possibilities.

2. Content reiteration
How many times do you post new posts from your blog to social networks? As a rule, optimizers send a fresh post to users' tapes, collect likes and comments, and that’s it.

The experience of Ahrefs experts shows that republishing content increases engagement:

3. Create quality content
This is the most obvious, rubbed to the holes advice to promote your blog, product or website through explainer videos. But also the most effective. As long as your publications are reduced to listing well-known facts under a different sauce, there will be no sense. Your goal:

create useful publications applicable in practice
give the user value and benefit
induce emotions
But what is this quality, useful, valuable content?

What is wrong with most quality content:

lack of novelty - as a rule, extensive publications collect tips, recommendations, facts, data from open sources available to all users. And if users are interested in the topic, then the probability is high that they are already familiar with this data.
lack of personal experience - only personal experience will allow you to create original, valuable, important for the audience content.
That such content is shared on social networks, recommended, quoted in other publications.

Valuable, high-quality, original content is the best way to promote a blog. The presence of experience and original ideas for publication does not exclude such important factors as:

the ability to correctly present ideas
the ability to correctly convey the publication to the interested audience (see paragraphs 1.2)
4. Organic traffic
Search engine optimization is needed for any publication, even the most valuable and useful. It is important to optimize the content:

under appropriate keywords , this does not mean that in every second sentence a key or a derivative of a key is used. This means examining key requests in order to understand how and what target users are searching for by topic.
by user intent - content must be consistent with the intentions of users
in form and format - content must meet user expectations
Ahrefs recommends analyzing the most popular subject blogs in the TOP of the search results to determine the format, volume and other factors.

5. Get in touch with the right people.
If you create excellent content that is useful and valuable to users, then the promotion of thematic influencer will be the best way to promote.

To make cooperation successful, always ask yourself a question before sending an article to an agent:

Why does this person have to share the material in his news feed / with his audience?

Significant reasons to propose to the influencer an article for distribution are:

mention of the infuenser, his works, merits in the promoted material or in the materials of the promoted blog
the material reveals something new in the topic, which the infuenser is very interested in, but does not yet know
6. Activity in thematic communities
There is a difference between the promotion of a blog in thematic communities of social networks and a full-fledged member of the community.

Attempts to promote in groups of social networks are often reduced to the publication of posts and responses to comments. It is important to be active not only in their publications, but also to participate in the life of the community, other discussions, and help other participants.

By the way, this will help promote the blog much more, since you can provide links to relevant subject articles in your answers.

7. Optimize content for different platforms and audiences.
For example, reformatting a blog's posting to a YouTube video will help reach an additional audience. For Instagram, you can extract statistics from an article and format them into infographics, presentations, podcasts, and so on.