Include names and addresses if possible. Usually, the guide will include suggestions to write letters. It could also suggest that the reader attend a hearing and testify. If a Bill is under consideration, the letter can suggest voting one way or the other, or it can recommend the member introduce a substitute Bill or an amendment. If the Bill has passed through Congress, it may be possible to make a recommendation to the President to sign it or to veto it.
Similar suggestions apply to state legislation.
If there is no specific pending action, you can suggest writing a letter to the editor of a newspaper. Timing is crucial. Your comments and suggestions on this document are welcome.