The actual design part is only half of the equation, a really important other half is the communication part: getting to know people, asking after them, small talk, etc..
Over time, the relationships you build with your clients are super-important. You’re ideally building a base of clients who you’ve worked hard to get to know a little.
I am terrible at remembering all this, so for certain clients (not friends I work with regularly) I’ll keep notes. This is all, technically, CRM: Customer Relationship Management.