When I started I used a coffee cup. It worked just fine. I now have most of my soaps in their own glass containers with lids. I soak my brush in a bowl filled with hot water. When ready I shake out the brush and swirl it around the soap dish loading it with soap. Heading to the bowl to build my lather. I repeat the loading of the brush until I have enough to whip up. If you have excess water surrounding your puck of soap you need to dump it out. Too much water thins out the lather.
Happy shaving