Hone your own Spanish skills. If you are a native Spanish speaker, make sure you can spell the words correctly and that you are familiar with proper grammatical structure. If you learned Spanish on your own or in school, brush up on common vocabulary words.
Consider your other teaching qualifications. Are you a teacher by profession? Have you ever taught or tutored before? Have you worked with children in any other context? When looking for a tutor, parents will look for someone who knows the subject material and can relay the information well.
Market yourself by telling parents that you are beginning to tutor Spanish.
Ask local schools if you can post notices in their hallway or office with your phone number so students can contact you. Introduce yourself to Spanish teachers at local schools so they can recommend your services to their struggling students.
Consider applying to a professional tutoring company for full- or part-time work. A pro of a such an arrangement is that the marketing and screening process is taken care of for you, but the con is that a cut of your profit will go to the company.