If it's not been said before, staying open past 3 or 4 PM, and have weekend hours. I work full time, tutor and have a 2 year old. I can't make it to one of the LQS's by me because they open at 10 or 11AM and close at 3 or 4. Only if I have a day off (summertime) can I get there.
Be friendly! I took my then 18 month old daughter in and the woman behind the counter told me that if she got loud I'd have to leave. I was the only person in the store! And all my daughter did was say "Mommy pretties" and pointed to fabrics.
Have some free sew-ins. The same LQS I mentioned above charges $30 to come and sew for 2 hours if you bring a "pre-approved" machine. Otherwise you have to rent one of theirs and it's ridiculous.