I'm no SEO guru but 3 months ago had this very question burning my entrails.
I'm writing 2 posts 3k words long per week and use social medias extensively.
I'm focused on quality and give detailed reviews on movies (ha-ha, I wont put link to my blog, I respect this place that much

)
I've reached 100K visits per month and have 5k+ subscribers.
Thanks to BHW, I've totally revised the way I've been doing keyword research, now focusing on the intent of the users.
The key for this is to gather the best semantics (also heard this called the semantic core or semantic kernel or keyword pool).
So go collect your keywords.
Arrange them by intent.
Filter trash.
Maximize keyword pool with clustered keywords:
Arrange them by intent.
Filter trash.
Maximize with search suggestions:
Repeat:
Arrange them by intent.
Filter trash.
Also it's advisable for bloggers to know what direct questions users pose. So focus on questions that contain your seed keyword. I don't know how you filter keywords to show only questions in Google KW Planner so you either will do manual research or apply filters of your tool.