Martinez is a fine artist, muralist, fashion illustrator, designer and educator. He was the Artist-in-Residence at the Long Beach Museum of Art for several years teaching art to students in the Local school district. And he was Artist in Residence of the Museum of Latin American Art in Long Beach for four years. His main thematic focus is the woman, whom he respects and reveres. He depicts her in vibrant color using a variety of media. He examines and celebrates women of diverse ethnicities on multiple levels and in different settings. She is powerfully portrayed in romantic, exotic, and mundane environments. We see her swaying and dancing to Latin rhythms. We find her on a solo vacation; shopping with unlimited purchasing power; dining and dreaming of past lovers and recent secret encounters. Martinez also sensitively probes the female psyche, a woman's innermost dreams and desires, her complicated and unpredictable spirit, attitude, desires, frustrations, passions, and fantasies. In other works, Daniel deliberates upon the woman in a social context, such as in "Service With a Smile", where a cocktail waitress serves drunkards at happy hour. She endures their gestures and bawdy comments to pay for her college education. In his "Garden Love," a montage of textured fabric materials that portray one of Martinez's female friends, the layers of fabric represent the inner tiers of her personality and her transformation through the years that he has known her.