Hummingbird Food
The simplest way to attract hummingbirds to your yard is to plant some of the flowering plants that they naturally feed on such as trumpet creepers and honeysuckle, but these aren't always located where you want them.
There are a number of different hummingbird food recipes, but sometimes it's just simpler to buy it and mix it up, and you can keep it near your hummingbird feeder. Here are some nectar products from Duncraft and Yardiac.
Put your feeders in a shady area to help discourage bacterial growth and mold as they can thrive in the nectar. Clear the old nectar out at least once a week and clean the feeder with a vinegar solution or a mild soapy solution, but be sure to clean out the soap! A good bottle brush can be a big help, and there are some that are designed to fit easily into a feeder.