Dealing with airy lather (large bubbles)
Here's something I've discovered through my limited experience with hard soaps:
I normally face-lather using circular motions. Using creams, this is nearly fool-proof, and the 4-5 types of cream I've tried produced nice thick lather. Hard soaps on the other hand (Mitchell Wool Fat specifically) tend to be more finicky about the amount of water in the mix, and it's easy to end-up with an airy lather that has large bubbles which collapse easily.
I found that by starting with circular motions on the face, I could build the initial lather, and if I found that the bubbles were too large, switching to painting motions quickly transformed the airy foam into thick lather. I know that a lot of people recommend hitting the puck to load more soap, but this didn't work very well for me.
I can't explain the physics behind this, but I know it works consistently for me... Hope this can help someone struggling with the same problem I had!