The fundamental do's DO address your senator or representative properly. DO write legibly. Handwritten letters are fine if they are readable. DO be brief and to the point. Discuss only one issue in each letter.
Quality is more important than quantity.
DO identify a bill by number or title if you can. This helps your representative or senator's staff know which bill you are referring to if there are multiple bills on the same issue. DO identify yourself. Indicate the state, congressional district, city or county in which you are a voter. If you have family, business or political connections related to the issue, explain them.