Most keyword research guides stop at the main phrase. They hand you a score, a traffic estimate, and a bill for the software. I have never needed any of that for a small blog. What I would do first is much simpler. This post explains how I take one main phrase and find the related phrases around it. By hand, for free, using a search engine and a bit of patience.
What a related keyword is
Start with a main phrase. Say I want to write about keyword research. That phrase is the centre. A related keyword is any phrase connected to it that people also type. “Keyword research for beginners” is related. “How to do keyword research” is related. So is “simple keyword research”.
These phrases are not competitors. They are the same subject in different words. My job is to collect them, not to pick one winner.
Where I look first
What I would do first is type my main phrase into a search engine and stop typing. The suggested searches in the box are the first group. Those are real phrases real people typed before me.
Then I press enter and read the results page. There is usually a section of related questions near the bottom. I write each one down, in the words people used. I described this hunt in my post on choosing topics, but I never gave it its proper name. It is a related keyword method. It always was.
The three places rule
I keep the same rule I use for topics. When a phrase or question shows up in three places — suggested searches, related questions, forums or comments — it earns a place on my list. One appearance could be noise. Three is a pattern.
I also listen for the things people say instead of my main phrase. If I keep seeing “easy” and “simple version” and “cheapest” around my subject, those are related phrases too. They tell me what people actually want from the topic: not the full agency version, the small one.
How I group them
A list of related phrases is not a plan yet. Next I group them. I put the main phrase at the top, then sort the others underneath by what they ask. Questions about starting. Questions about tools. Questions about cost.
Each group becomes a heading in one post. If the group is big enough, it becomes its own post later. This way several related phrases point at a single piece of writing, and each heading answers a phrase someone actually typed.
Why I skip the score
The big guides rank keywords by a score. Ahrefs found that most pages get no organic traffic at all, and its answer is better keyword research, which usually means its tools. I do not argue with the finding. I just do not need a score to see that “keyword research for beginners” belongs with “simple keyword research”. Related phrases are cheap to find and free to use. For a small blog, that is the whole method: one main phrase, a search box, a results page, and a group of headings that answer real questions.