Make t-shirts and sweatshirts with your logo and name on them. Have all the kids where them when you go on a field trip. People are sure to notice. Offer three mornings of free daycare at a silent auction. Contact your local hospital.
Most hospitals send out some sort of a welcome package to all the new babies.
Ask if you can put a flyer or business card in it. As with business cards, have some inexpensive pens made with your daycare name and number. Also, give them to your current clients and ask them to pass them around. It's best to place a classified ad in the Childcare section, rather than a big display ad, if you're on a limited budget. Offer your current families a Referral Discount.