Jensen made his first piece of jewelry in 1899, a silver and gilt "Adam and Eve" belt buckle. This led Jensen to make a landmark decision, when in 1904, he risked what small capital he had and opened his own little
silversmithy at 36
Bredgade in Copenhagen. Jensen's training in metalsmithing along with his education in the fine arts allowed him to combine the two disciplines and revive the tradition of the artist craftsman. Soon, the beauty and quality of his
Art Nouveau creations caught the eye of the public and his success was assured. His silver and jewelry designs from this period often featured plump abstract organic shapes and were accented with gemstones like amber, garnet, citrine, malachite, moonstone, and opal. This approach reflected his personal style, which was rooted in the Art Nouveau movement, but also transcended it with a more streamlined version popular in the 1920s and 1930s. The Copenhagen quarters were greatly expanded and before the end of the 1920s, Jensen had opened retail stores in Berlin (1909), London (1921), and New York City (1924). In 1930,
Adda Husted Andersen worked for Jensen in New York City,
enameling homewares. ==Museum collections and exhibitions==