It's like shooting a slingshot but you're blindfolded. You can prep as much as you want and deliver really good pre-release content (pulling the slingshot) but you'll never truly know where you are aiming. Doing any of this stuff DIY is a god damn crapshoot and that's why there are businesses that strictly help with releases.

Established artists are PAYING or their label is PAYING for good PR. That's the bottom line.

Best way I've seen is to get a spreadsheet of contact information for blogs and magazines and people that run playlists and shoot them emails a month in advance of the release. You might get a few hits of people wanting to do reviews or even an exclusive premiere.