It is pretty easy to qualify for the LARE in Louisiana. You need to have a degree in landscape architecture and at least 1 year of experience working under the direct supervision of a licensed landscape architect, arborist, or landscape contractor.
After meeting the experience requirements, sign up for the LARE though CLARB. Once you pass all sections of the LARE, you can apply to the State of Louisiana for licensure. You also have to pass a state-specific Louisiana Plant Characteristics section of the LARE which is administered at the same time as the LARE.
Check out his blog post for detailed information on becoming a licensed landscape architect in Louisiana. It has links to the application page and breaks down the process in easy steps. Good luck.