You can definitely draft your own agreement. However, since some of this can get complicated, a lawyer who knows the law regarding these agreements will be an important resource. They can review your agreement and make sure that it says what you want it to and meets state legal requirements.However, since prenuptial agreements are scrutinized by the courts, having 2 independent attorneys advise each of you might be a good idea, although most courts don't require that each party to a prenup have their own lawyer.