The Fordham Institute has been a staunch supporter of the Common Core standards. But reviewers there have noted specific improvements that a few enterprising states have made to the standards, as well as some other areas where improvement is clearly possible. Their recommendations include the following:
Recommendations for English language arts
Further develop the disciplinary literacy standards—especially for grades six through twelve.
Clarify the differences between ninth and tenth grade and between eleventh and twelfth grade.
Make targeted improvements to the writing standards.
Recommendations for mathematics
Articulate clear pathways in high school math that are explicitly aligned with specific post-secondary and labor market outcomes.
Add standards for advanced high school math courses.
Recommendation for both subjects
Take another look at the alignment between K–12 and pre-K.
For more information about each of these recommendations, see https://edexcellence.net/articles/advice-for-states-hell-bent-on-revising-the-common-core