What about doing a title like, "Mrs. ____, Be sure to mention that I..." and then have each child list the things s/he hopes you tell his/her parent or guardian? You could have them do this writing on bordered paper or plain paper mounted on construction paper in the shape of an ear as if they are whispering the big news.
Or use paper that looks like the front of a newspaper and have them write the headlines news their parents should know about their perfomance in major areas like science news, ss, math, reading, behavior, etc.
Or give out giant stars and have them write the area in school they really shine in with a title like "I Really Shine When..." or "I am a Stellar...."
I always have some writing available for parents to read and enjoy. Plus, you don't need to do corrections if you are pressed for time or want a true sample. That way, you could refer to the board when you are trying to tell the parents that the child does do well in spelling, identifying types of sentences, etc. when tested but may not always be careful enough to apply it in every day situations. Very effective for making a point. Just be sure to alert the children about how everyone will be seeing an example of their writing so they need to work carefully and proofread before handing it in.