After using a paring knife to quarter the yuzu, push the flesh into a strainer resting in a bowl, smash it with a rolling pin, then finally squeezing the last of the juice out with your hand.
Cubes can be dropped into, oh, I don’t know, pints of Yona Yona Ale, sautès. for dressings. when I get my hands on some peppers (とうがらし), I will make my own yuzu kosho.
I’m half done, so maybe fifty yuzu gets you two small trays, but they are extremely concentrated flavor-wise.