Cindy Merten suggested:
We post a "Conduct Covenant" in each of our rooms and ask our teachers to review it with the kids each week. I know they don't always do it, but it seems they have done it often enough, because we have few discipline issues. It's illustrated and in color and reads as follows:

Conduct Covenant

1. Pray for one another.
2. Treat everyone with respect. Put-downs are not acceptable.
3. Raise your hand and wait to be called on.
4. Listen when others are speaking.
5. Keep your hands, feet and all other objects to yourself.
6. Follow directions as they are given.

Connie posted:

Our Christian Development Committee developed this "Code of Conduct" and we share it at the beginning of each church school year with teachers/leaders, children and parents and put it in the fall newsletter - with occasional reminders along the way. We post it on bulletin boards as well. It has helped!

CODE OF CONDUCT

Basic Assumptions
- each person is a child of God who is gifted with unique talents and abilities
- each of us is called to lead and to learn throughout life
- as a leader, one is called to prepare faithfully, to seek God’s wisdom and insight in one’s preparation, seek the input of learners and incorporate it into the learning process, to be respectful of individuals as children of God
- as a learner, one is called to participate openly, offer input in a positive way, to be respectful of the leader’s role

Therefore, each teacher/leader in the church school shall:
- endeavor to create a welcoming, open environment in the church school and classroom
- prepare faithfully
- be open to the suggestions of the children and young people in their class/group about the learning process
- deal with challenging behavior in a caring, responsible way

Each child or young person in the church school shall:
- help to create a welcoming, open environment in the church school and classroom
- be courteous and respectful of the teacher/leader in their classroom and in the church school
- be helpful and respectful of the needs of other children/young people in the class
- offer suggestions about the learning process in a helpful and positive way
- understand that disruptive, discourteous behavior interrupts the whole class and will result in a return to parents in the worship service and/or a meeting with their parent(s)

Each parent with a child in the church school shall:
- help to create a welcoming, open environment in the church school and classroom
- talk with their child(ren) about openness to learning, respect for teachers/leaders and how disruptive or discourteous behavior negatively affects the church school experience
- understand that on-going disruptive, discourteous behavior will result in a return of children to parents in the worship service and/or a meeting with their child’s teacher and/or a request for a parent to assist in the classroom
- accept responsibility for their child(ren) and deal with challenging behavior in a caring, responsible way

This code of conduct has been developed and reviewed in co-operation with the Christian Development Committee.

Here are some tips you can implement and share.

Feel free to respond with your own. 

"Five Things Parents Can Do to Get to Sunday School On-Time"

Pre-worship hour Sunday School has long suffered from late arrivers (and non-arrivers). Many families simply lack the good advice to get them up and moving in the right direction. And with more adults working weekends, more second shifts, split families, and too many things to do on Sunday, teachers can help parents by sharing these tips:

1. Lay out church clothes the night before.
2. Set a Saturday night bed-time.
3. Set conditions for those who try to stay home (no TV or cellphones, no friends, do chores).
4. Plan a post-church lunch at a park or restaurant and make advance plans for church friends to join you. 
5. Volunteer to do something on Sunday that includes your kids. Specific commitments are great motivators.

Five Things Teachers Can Do to Encourage On-Time Attendance

1. Start your lessons on time and with something interesting. (Nobody likes to miss out.)
2. Create a snack list and make calls to sign-up and remind parents (or make this the responsibility of the parent who is having trouble getting their child to Sunday School).
3. Identify the perpetually late-arrivers and invite their parent to help lead.
4. Deal with "lingerers." Be aware that some late-arrivers get to the church on-time but like to hang out in other spaces then arrive late. Talk with their parents about this. (It's a security issue as well.)  Know where they are lingering and have a volunteer walk them to class.
5. Personally share the "5 Things" list of ideas with parents.

How to Reduce the Distraction of the Late Arriver

1. When the late-arriver enters the room, immediately have them come sit by the teacher. This will keep them from causing an "entrance commotion" among their friends.
2. If you have a helper, make it their responsibility to quietly greet the late-arriver and plug them into what's going on. Some students love to "make an entrance" and your helper should shut this down. 
3. Do not "recap the lesson so far" for late-arrivers. Keep teaching as if they were there on time and bring them up to date quietly.