Whether you retain a lawyer to draft contracts or to represent you in court, the outcome of your case will depend largely on how well you work with your lawyer.
A lawyer is not a magician or a mind reader. Your lawyer needs to know all of the information available to you in order to best represent your interests. For instance, if you were in a car accident and you noticed that the other driver was on the phone, keeping this information from your lawyer could substantially harm your case.
A good lawyer will listen to you and ask you questions. A good client will tell their lawyer everything about their case.
So, a good place to start is to write down everything you can remember about what led up to the lawsuit. Or, in the case of a contract, all of the terms that you would like. Then sit down with your lawyer and go through the list. The more you provide ahead of time, the better. For each fact, try to answer the question “how do I know this”?