When students are not following behavior expectations, Fix-It Tickets are a constructive next step for some self-reflection on the part of the student. Rather than just tell a child what they are doing wrong, this tool allows for a more effective way of having them be the one to evaluate their own behavior and think about WHY they should work to fix it. After the student fills this out, it can be used as a jumping-off point for discussion when you pull them aside to talk privately about how they can make it right. You can choose whether you want to send their Fix-It Ticket home to parents or not, or it could be useful to show parents at a conference.
This resource includes a ready-to-print template as well as an editable version to customize with your own behavior expectations.
If you have a chatty class and the primary behavior problem is blurting/side discussions/talking at inappropriate times, you might also be interested in this resource: Catch a Bubble: Classroom Management Resource for a Chatty/Talkative Class