You can put a masthead right under the official letterhead. Use the same layout design for at least a year to establish an identity for the audience. Select subdued colored paper, appropriate for audience, or use white. Use paper heavy enough that the ink can't be seen through the paper. Use clip art.
Clip art is available from many sources.
Most computer layout programs have some pieces in them. Clip art can make a page look open and easy to read. Characteristics of good clip art are that it is appropriate to the subject, adds information and not just decoration, and gives all members of the audience the chance to see themselves. Plan when to update the mailing list, such as asking readers to contact you if they wish to continue receiving it. Plan for evaluation.