Send a short "Welcome to the team" message to let new employees know how excited you are to have them. Here's how to make the best first impression.New Hire Welcome Letter Template. 1. Enter the date at the top of the letter. 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. Need help or just some ideas to welcome new members? We're thrilled to have you joining us and look forward to adding your unique skills and experiences to our amazing team. Your new member welcome letter should sound true to your organization's brand and mission. "Congratulations on becoming the newest member of our office!