Have you had training and experience in drafting or related subjects? The amount that you have had, great or small, will give you a basis for additional training, or possibly for specialization in some particular kind of drafting work.
Actually, no occupation offers such opportunity for individual development than drafting. There are so many disciplines of work that the drafter is called on to perform. The engineer, architect, shipbuilder, surveyor, and patent attorney make constant use of his or her originality and knowledge; to these professionals, they're priceless.
A machine or apparatus is going to be manufactured, a building is going to be built, a ship is to be constructed, a map has to be made, an application for letters of patent is needed to be filed; the draftsman, or drafter as they are called today, is first to be called on to draw the details for construction and to make illustrations of these things as they're needed.