"Nice to see you again" - that warmed my heart and brings me back to a shop 45 min. from my house. I pass by 3 other shops to get there.
Open on Sundays for working people. In fact, open consistently. Nothing's worse than arriving at posted hours to find the place closed for no apparent reason. I hate having to call first to make sure they are open.
Calling or emailing me to tell me a fabric that they ran out of is in. Offering to mail me more when I run out so I don't have to drive 45 min.
A place to put down your bolts of fabric if you are buying or auditioning a bunch. This place should not also serve as the cutting or paying counter so as not to create a bottle neck for others.
A nice variety of fabric, some of which may NOT be the style of the owner(s). Just because you like "country" doesn't mean everybody else does!
A sale area, and discounts for birthdays (mine gives me a percentage off that's 1/2 of my age).