Choose a sunny location if possible. Butterflies are more active in a warm environment and more sun results in more flowers. An area sheltered from the wind also encourages more activity.
Vary plant height, placing short plants in front and taller plants in back. This gives hummingbirds space to hover, and affords you a better view of both plants and birds.
Stagger bloom time to attract hummingbirds and butterflies all season. While red flowers do attract hummingbirds, nectar production is more important than color.
Try to plant several of each flower, placing them in different locations. This encourages more hummingbirds, who are very territorial and try to keep others from their personal space.
Lastly, provide some water in the form of a low birdbath, small pond, or pool. Hummingbirds need water for bathing, and butterflies need water to aid in ingesting nutrients.