Having a little distance between the photographer and the object isn't necessarily a bad thing for this kind of work. Lighting is important and you generally don't want to be so close that you get in the way of the lights. As far as having enough DOF, focus stacking is one way to go http://www.cambridgeincolour.com/tutorials/focus-stacking.htm, another is to rent a tilt/shift lens which will allow you to change your plane of focus in such a way that having a small DOF becomes manageable. Focus stacking is the easy route, learning how to properly use tilts and shifts is the more difficult, but ultimately more useful in my opinion.

Having a little distance between the photographer and the object isn't necessarily a bad thing for this kind of work. Lighting is important and you generally don't want to be so close that you get in the way of the lights. As far as having enough DOF, focus stacking is one way to go , another is to rent a tilt/shift lens which will allow you to change your plane of focus in such a way that having a small DOF becomes manageable. Focus stacking is the easy route, learning how to properly use tilts and shifts is the more difficult, but ultimately more useful in my opinion.