Identify your use case: cocktails need a bright herbal finish, while baking needs balanced sweetness without turning bitter.
Choose the substitute closest in flavor direction from the list: spirit-forward (chartreuse family), honeyed herbal (ginger/honey), or fortified sweet (sherry + honey).
Apply the listed ratio first; if your batter/dough becomes too wet or the drink tastes too sweet, reduce the substitute slightly and compensate with a small pinch of salt or a tiny splash of citrus.
For baking, test after baking: if you miss the herbal brightness, add a small amount of lemon zest or a few drops of bitters next time rather than doubling the liqueur.
Taste before serving for cocktails; if the finish isn’t herbal enough, add 1–2 dashes of bitters rather than more syrupy sweetener.