Here are some more tips from Dale Carnegie's book, How To Win Friends and Influence People:
1. Mention The Member's Reputation
If you tell the member of Congress, or his or her staff, that they have a good reputation for something, they will want to embody those characteristics and will work hard to live up to them. For example, if you start off a meeting by saying, "Thanks for meeting with me. You have a great reputation back home for standing up for what is right," they will immediately be motivated to live up to those ideals.
2. Let The Staffer Talk
People enjoy talking, so you must work hard to be a good listener. After you have made your pitch, let the staffer rationalize and talk about the idea because it will sound much better to them in their own words.
3. Lead The Staffer To Yes
If you and your member of Congress do not see eye-to-eye on an issue, emphasize and highlight the things you do agree on. One trick is to ask them simple questions where they will always answer yes. Starting off by getting the staffer or member of Congress to answer yes will increase the likelihood of him or her saying yes later on. For example, you can start a conversation by asking them, "Can I tell you about a policy that will lead to more jobs in your district?" or "Would you support a policy that is proven to help out our veterans?"
4. Talk About The Staffers Interests
If you speak with a staffer or a member of Congress, ask about what they are interested in. When you ask people about their interests, they feel valued. When people feel valued, they, in return, will value you. The best thing to do is find out what their interests are beforehand. For example, if your member of Congress also represents Hershey, PA, talk about chocolate. If their Alma Mater is good at football, ask them about the upcoming season. Try to find out what interests them and bring it up naturally in the conversation.