Start from outcomes, not opinions
List your most valuable customers, judged on retention and profitability rather than headline deal size. Then list the accounts that churned quickly or were painful to serve. The profile lives in the difference between those two groups, and a workshop that skips this step will produce a description of the market the company wishes it had.
Look for predictive attributes
Many shared characteristics are descriptive rather than predictive. If most of your customers are in one city, that may simply reflect where your first salesperson had contacts. The attributes worth keeping are those that separate strong accounts from weak ones, which means checking each candidate against both lists rather than only the good one.
Write it so it can be applied
Each criterion should be answerable about a company from public information or a short conversation. Attributes such as forward-thinking or growth-minded fail this test. Attributes such as between twenty and two hundred employees, handles most enquiries by phone and messaging, or operates across more than one location can be checked.
A worked fit-scoring example (illustrative)
Choose four criteria and weight them by how strongly each predicts a good outcome: industry weight 3, employee band weight 2, operating model weight 3, geography weight 1, for a maximum of 9. An account in the right industry, in the right size band, with the right operating model, but outside your usual geography scores 3 plus 2 plus 3, or 8 out of 9, and is a strong fit worth outbound effort. An account in the right geography and size band but the wrong industry and operating model scores 3 out of 9, and should go to a self-serve path rather than absorb a salesperson's week. The scale is arbitrary. What matters is that the same rule is applied to every account, so priority is a consequence of the profile rather than of who happened to reply most enthusiastically.