Start by juicing fresh limes, lemons, and oranges. Combine the juices in a bowl or a small pitcher.
Mix the juices thoroughly to ensure a consistent flavor profile.
If you prefer a slightly more pronounced tang, add a pinch of citric acid to the mixture. Be cautious not to add too much, as it can overpower the taste.
Taste the homemade key lime juice substitute and adjust the ratios of the lime, lemon, and orange juices to achieve the desired balance of flavors.