You apply makeup nearly every day, so why spend the extra cash for a professional? A professional makeup artist (you can find their services on the menus of most high-end salons) will do your makeup onsite using her own tools and products, so you don't have to worry about whether you remembered to bring mascara. Schedule a test run about two weeks before your wedding day; this hands-on consultation will give you a chance to tweak the details. Remember to bring your veil or any other hair adornments with you.
On your big day, you'll be camera-ready for hours, and that's a benefit that's hard to beat. Plus, most makeup professionals can be hired to apply their skills to the entire wedding party; it's a nice treat for bridesmaids who've stuck by you as the big day nears.