Your keyword strategy should make clear which “keyword groups” you focus on. It doesn’t have to be a long list of keywords (though it doesn’t hurt to have one). Your keyword strategy should be a definition of a group of keywords that you’re tackling. Every time you’re writing new content you can have a quick look at those groups and pick a new keyword that falls in line with the strategy.
These keyword groups should be inter-related too of course; if you can never write posts that touch on multiple of your main subjects, they’re simply too far apart.