International Law encompasses almost all legal practice areas. Whenever the laws of more than one country are involved, the legal issues become international. Therefore, no single practice area can be called "International Law." For example, all of the following fields can have significant international components: human rights, trade, environment, securities, commercial lending, tax, representation of foreign governments, litigation, arbitration, joint ventures, direct investment, military, mergers and acquisitions, intellectual property rights, and project finance. Therefore, international law is an extremely broad area.
Familiarize yourself with the organizations and resources that can shape your choices. Consider joining the Human Rights Law Society, U.S.-Mexico Bar Association, International Law Students Association, and/or the American Society of International Law. Contact UT Law mentors (alumni) who have had international experience; attend the numerous panels related to international law; and speak with professors who have specialized in the global field. In addition, "Finding and Funding International Public Interest Opportunities" on PSJD is a useful resource. It will also be important to you to determine which area(s) of law in the international field interest you most.