To make hummingbird nectar, mix one part sugar to four parts water. Stir the mixture as you heat it on the stove until it begins to boil. Remove it from the heat and let it cool to room temperature before pouring it in the feeder.
Cane sugar is the best kind to use, although beet sugar is not harmful to hummingbirds. Never use artificial sweeteners, brown sugar, honey or any other substances. You can add slightly more sugar in cooler weather, but do not exceed a ratio of three parts water to one part sugar. More than that is likely to clog the feeder.
Do not add red dye, because it is unnecessary and some dyes may be harmful to hummingbirds. The bright colors of your hummingbird feeder are enough to attract the hummingbirds. If your feeder's color is dull, you can also tie a red ribbon to it.
The hummingbird nectar can be stored in the refrigerator for up to a week, so you can make a large batch for convenience. Change the nectar in the feeder at least once a week, and thoroughly clean the feeder each time you do it. This helps prevent the nectar from spoiling, which can make the hummingbirds sick. Hanging the feeder in the shade and changing the nectar more frequently during very hot weather can also help prevent that.