Choose the leave behinds that best suit your purpose.
Think about how much information you want to communicate, and what kind of medium will work best for you. Are you a house painter and want to leave customers with detailed information about your pricing and services? Choose a leave behind like a brochure, where you'll have plenty of space to print this information.
Also, consider whether there's a certain kind of leave behind that matches up with your small business. If you're a plumber, maybe you can leave a cheeky door hanger on your customer's bathroom door knob. Do you run a home cleaning service? Leave your customers with a bottle of branded hand sanitizer.