Methods, systems, and devices according to this invention provide drill guides for optimal placement of fixation elements, such as half pins, into a patient's bone. According to one embodiment, a collar frame with a collar adapted to receive a bar of an orthopedic external fixation system such that the collar may be moved linearly or rotationally about the bar is coupled to a guide frame including a bore through which a fixation element of the external fixation system may be inserted. The coupling between the collar frame and the guide frame allows for them to rotate about at least one axis relative to each other. In one embodiment, the collar frame and the guide frame may rotate about three axes relative to each other.