In my class, I assess each standard or concept twice in class and take the student's highest grade. If they still don't do well, they can correct their old quiz and come in for a retake.
This product is a complete collection of quiz retakes and an answer key for each concept. It covers every concept (which you can find for free in my I Can Statements product)! I use these throughout the year, but you could also use them as a review of each concept or as remediation.