If you do not have the skill set required, outsource.
A lot (if not all) printers wether in town or online have some sort of design team they have in-house, some are better value than others. By this I do not mean cheap, I mean value, the quality, professionalism and turn around v cost involved.
The client will appreciate only having to deal with you rather than a range of businesses. Gets one invoice and one point of contact.
The first thing to do when you receive an interesting leaflet is check the website. Every business should have one. It validates who you are and what you do.
Look at a leaflet as a gateway to your website and always have the relevant information on the leaflet so customers can go straight to your site.