There are several ways to lather a shaving soap, but for PANNACREMA the following method is best, because it allows you to get consistent results by controlling the amount of soap and water used.

• Soak the brush for about fifteen minutes in a bowl of warm or hot water.
• Shake and wipe the brush thoroughly to remove all excess water. The brush should only be moist.
• Empty all the water from the bowl and shake the drips out. It should be no more than damp.
• Pick up a piece of soap the size of a hazelnut.
• With one hand, clasp the brush tightly around the top of the bristles (to stiffen it), then with the other hand apply the soap, spreading it all over the tips of the brush.
• Begin the first lathering phase, by holding the brush normally and twirling it this way and that in the bowl. 
• If you are using a boar brush, or one with stiffer bristles, it should only take 30 seconds, whereas with a badger or softer bristle brush, you will need a few more seconds.
• At this point you should have obtained just a light lather; that's fine because the goal of this phase was only to distribute the soap well over all of the brush tips.
• Now add some water, a few drops at a time. The number of drops depends on several factors, such as the hardness and temperature of the water, the type of brush etc., but let's say between 5 and 30 drops. Of course, you can always add more water, but you can't remove it once it's there.
• Finish the lathering by twirling the brush for another 30 to 40 seconds. If, after this time, the lather is still too thick, add a few (say five) more drops of water.
• At this point your lather is ready, but if you want to get a super-rich, luxurious, extra lather, then you can add a small amount of extra soap, the size of a coffee bean, again picking it up and spreading it over the brush tips before twirling the brush a little more in the bowl.