Getting a good shave from a good pre-shave...
I use the Williams and Conk occasionally too, here's what I've found.
1. Soak the puck and brush in hot tap water while showering.
2. Give the brush a few shakes (2-3) to get excess water out.
3. Drain water from puck and swirl the brush (don't press to hard, just enough to make firm contact).
4. Keep swirling until you're making lather in the bowl/mug the soap is in...then keep at it for another 20 seconds or so.
5. Wet face with hot water and start making lather on your face. About a minute or so.
6. You can gradually add water by dipping the "tips" of the bristles in the hot water the brush was soaking in.
I face lather mostly and find if I load the brush up really well in the mug, the hot water on my face mixing with the loaded up brush makes a good ratio for me. If its a bit too much soap, I dip the tips of the brush in the hot water and continue working the lather into my face. Trial and error really, but you should be able to use any of those soaps mentioned with success after some practice.
Remember, you don't have to shave to practice making lather :)
Cheers!