After a model has been loaded, the initial location of the Box Tool is centered about the look-at point - the geometric center of all visible geometry - and is aligned with the model axis system. The coordinates of the Box are specified with respect to the default frame: frame 0. However, if you have created additional frames, you can position the Box Tool relative to the origin of a different frame. This is accomplished by selecting the desired frame in the Which Frame list in the Transformation Editor dialog.

You can easily reset the position and orientation of the Box tool to the default. See Reset Tools and Viewports for more information.

Positioning a 3D tool with a 2D device (the mouse) can be difficult. Multiple viewports are sometimes helpful in positioning tools since you can see the tool simultaneously from multiple vantage points.