For Col. Conk Soap, I just use the plastic it comes in. 30 seconds swirling on top of the soap and 30 seconds on my face. I use a mid line pure badger brush. I have to lightly dip the edge in water to enhance the lather during the application to the face.
A candle warmer is a good idea for mugs as the colder months can quickly steal the heat from the mug. While shaving, you want to keep everything else warm to make the shave comfortable throughout.
I soak the brush in a 7-11 cup that has hot water in it and I rest the Col. Conk soap container on top of the cup (it floats a little). This keeps it warm while I shower.
Mugs, bowls, scuttle, work well with creams. But you can always use your hand to whip up a lather as well.
Lots of good ideas in this thread.
Pabster