In order to roughly place objects in a mockup the ability to drag objects along a particular axis or vector would be useful. While the snapping of faces, edges, and axes is useful for precise placement there are also cases where the placement does not need to be as precise, or a rough placement may be used as a first step in repositioning an object. Using a drag option the user should be able to move an object along the principal axes and planes by dragging or along non-principal axes/planes as defined by surfaces/edges in the mockup.
One option is to use a 'move triad' for this purpose. Are there other ideas on how best to implement a 'free drag' option?