Formative Assessment tells the student (1) where they are going (2) what they are now and (3)how they can close the gap.
The must important part of formative assessments is the feedback. Feedback should be individualized and tell the students how to improve.
In my book F.A.T. I share many formative assessment tools and ideas to track student process.
Here are a few ideas you can use:
Parking Lot Self -Assessment: A quick and easy self-assessment for students is a Parking Lot. Students rate their level if understanding and place on the board.
WallWisher: This is a digital formative assessment tool. I took a worksheet cut the problems out and allowed students to draw a problem. Each student solved their problem and posted the solution and the method they used to the Wall.