The process of constructing your knife begins usually with a conversation, ideally in person but not necessarily.
I’ll ask a million questions and if we’re in the same room, ask you to show me how you do a number of different knife-related things.
I have a huge collection of wooden templates to help gauge edge profile (how the knife moves on the cutting board) and a general sense of blade and handle shape and length. If you’re very far away, I can even send these to you. Either way, your hands almost always know what’s best for them and this part usually gets us to a particular style quite quickly.