I soak my boar brush, pinch the bristles together and rub the stick right onto the brush then start creating lather in a bowl. I find the soaps too hard to rub against my face. If i want to use my badger brush, i slice off a thin slice and smoosh it into a hot bowl and lather as per normal.
I like the Arko a fair bit but find adding a drop or two of glycerin greatly improves the cushion and feel of the lather!