I'm sorry to be the one to break this to you, but guest posting is pretty much dead.
I'm talking about commercial guest posting here.
These are blogs that are put up with the main intention of making money through paid articles with your link in it: guest posts.
Google has gotten wise to this.
In fact, it has gotten so scammy that a lot of people are saying that Google is more than fully justified in cracking down.
There is one way out.
Instead of doing guest posting, you should issue newsworthy press releases where you share actual industry or niche-relevant information that involves your brand.
If you are consistent with this, eventually, you become part of the conversation regarding your niche.
Don't be all that surprised when high-value media properties or high-value blogs in your niche start linking to you.
How come?
You have information that they're interested in.
Through your press releases as well as the content on your blogs, you become an authority.
That's what you should aim for.
Does this happen overnight?
Of course not!
It takes quite a bit of work, but it's definitely worth doing because paying for a link in the form of guest posting simply is not going to cut it anymore.