Oddy uses regular water-soluble soldering flux and avoids using paste flux since it is more difficult to clean. You must thoroughly wash flux off the panel as each layer is built. Do not solder a high-profile finished solder bead on the area of the panel which will be plated. This is so the solder doesn't raise the plane of the glass. If applying patina to the project, you must patina the plated layer prior to soldering it onto the base.
Some layers have to fit on top of each other very accurately.
There can be a problem of moisture buildup between layers. Venting between layers allows moisture to escape. To build vent areas, don't completely solder all areas. The solder will not stick to the Vaseline and will leave small vent holes for moisture to escape. Flux can 'spit' between layers when soldering.