Here are 10 things your welcome letter or email to new members must include plus a template that can be customized for your organization. A "thank you for joining" membership letter should include a personalized greeting to the new member.Use the member's first name in your salutation. Do you want new ways to welcome members into your church? Check out these top church membership welcome letter templates and best practices. Get help drafting the welcome letters to the new members of your nonprofit organization with these two useful writing templates! A good welcome letter acts as a travel guidepointing members to key resources, highlighting benefits, and outlining simple next steps. 1. Enter the date at the top of the letter. Here is a template for a new member welcome letter you can tailor for your own association or membershipbased organization. Parents or legal guardians will need to provide the following documents: Proof of Residency in Fairfax County.