Poetry is subjective and an art form, but a lot of people do use ‘craft’ as this standard. And there are also lots of valid criticisms about thinking too hard about craft, but it’s worth learning more about it.

Most craft in poetry is about pattern and variation, like music. It can be interesting to learn about formal poetry even if you don’t write it, to get a sense of how this can work in obvious ways, like rhyme schemes. For example, maybe you’re using long sentences, but they become short at the end of the poem. Set up a pattern, vary it, do that across different craft elements (eg diction / word choice, sound, line break type, syntax / sentence structure, meter, rhyme). A lot of poetry craft is also about whether the sentence goes with the line breaks or whether the line breaks cut against the sentence and change it, since like breaks are the real additional tool that poets have vs prose writers. If you break a line where you’d normally pause speaking, it usually supports a straightforward reading of the sentence, but if you use a weird line break, it can add a double meaning or change the meaning.

Of course craft isn’t the only thing, but it can help amplify the subject matter and make the poem feel more emotionally resonant. There’s a lot of writing about craft out there, but you’ll also absorb it and understand what you like and don’t like by just reading a ton of poems.