Identify how you’re using Lillet Blanc: mostly in a cocktail/drink, or as an ingredient in a sauce/baking mix.
Pick the closest match by flavor: Dry vermouth-based swaps for bitterness + herbiness; white wine + lemon/zest to restore the citrus lift.
Use the listed 1:1 ratio (substitute amount in place of Lillet). If your swap is less bitter, add a small squeeze of lemon; if too bitter, add a small pinch of sugar.
Let it sit 2–5 minutes (especially cocktails) so the aroma settles. Taste once and adjust bitterness (bitters/vermouth) or sweetness (micro pinch).
For baking or pan sauces, reduce very gently over low heat to concentrate flavor without turning harsh.