The hard cream came with an operators manual in Spanish, but luckily a fellow shaver over at my favourite shave forum translated it into English in his review a couple of years back:
Always leave the tub open and use the cap as a base. The reason is because Dr. Selby shaving cream (in the tub 3 times concentrated) will always have a dry surface and it will render 400 shaves. Only in case of travel cover the cream.
Wet the brush, discharge the water over your face then swirl the brush in the tub as shown in the image. This way the cream will not get wet and it will not waste too fast.
To multiply the cream production on your face. Wet the brush a little more and keep swirling until it turns creamy, compact with no air bubbles.