Focus stacking is a great technique, but it's off topic for APUG, so the question for this forum is, how to do what you want using traditional techniques.

Camera movements are a plus, if the subject lends itself to it. At very high magnification (say more than about 6x comparing the size of the object to the size of the image on film), DOF is going to be razor thin, so it's all about using the DOF you have most effectively. Diffraction does become an issue at higher magnifications, because the effective aperture is in fact much smaller than the aperture as set on the lens, so you may choose a wider aperture to get the sharp part of the image sharper, even if it costs you some DOF.

There are other problems when you go up in format--mainly you need more light. If you are using artificial light, then put the light as close as possible to the subject--really close, presuming the heat from your light source won't destroy the subject--to get as much out of the light you have. You need a really solid tripod, head, and ideally a macro focusing rail unless you are using a view camera with focus on the rear standard, and you may want to do things like sandbag the camera and add weight to the tripod. You may need to be concerned about the solidity of your floor. This is true whether you are using strobes or continuous lighting, because even with powerful studio strobes, you will likely need multiple pops to get enough light for the exposure.