At the beginning of the school year, I like to send home a questionnaire/survey for parents to fill out about their children. They know their children better than we teachers do, particularly at the beginning of the school year, and they are generally very eager to share their opinions, concerns, and advice about their children. This survey gives parents the opportunity to share their insights about their child's academic strengths and weaknesses, allergy/health issues, hobbies and interests, learning behaviors/work habits, student fears and insecurities, parent concerns, etc. I find it helpful to get this information in writing because it allows parents to be heard while making it easier for me to remember the information (much easier than if parents try to tell me this information during an Open House with dozens of students and parents crowding around at the same time).
This survey is also available in a Back to School bundle that includes a cover letter and a form for parents to fill out with contact information and preferences. That bundle is being sold as "Back to School Parent Teacher Communication Forms."