Use a lot of light to focus, even if you don't use that much light to make the exposure.

Focus with the rear standard or by moving the camera. Focusing with the front standard will be nearly impossible. Linhof makes a macro rail for LF.

Here's an example with a photo of the setup in my APUG gallery--

This was before I had a Linhof macro rail. I have a short Arca-Swiss plate on the Technika body and a 4" Arca-Swiss type plate on the bed, and I can slide the whole camera in the Arca-Swiss type clamp to focus. It isn't as precise as a geared focus rail, but it's not bad.