Post a Quick-Use Artic Run-Through in Their Room:

Make a poster with the words, sounds, or sentences that you’re working on in speech and either post it on a wall in the room or in a folder that the child keeps.  Ask the teacher to run through the words with the child once per day (whenever she has time).

Make a Beginning-Of-Day and End-of-Day Checklist:

Create a short checklist that the teacher is to go over with the child at the beginning of the day that reminds him what sound he’s supposed to focus on saying correctly.  At the end of the day, have the child and the teacher fill out a box that asks how the child did that day at remembering to use that sound (you can use smiley faces or a number rating scale to make it quick).

Create a Positive Reinforcement Jar:

Put a small jar in the room near the child’s desk and give the teacher a bag of marbles or something to fill it.  Ask the teacher to add a marble to the jar from time to time when she hears the child using the speech sound correctly (and tell the child that she noticed a good one).  Ask the child to bring the jar to you when it is filled for a reward.