Choose your goal: for closest citrus-lift, go with black pepper + orange zest; for the tingling effect, use toasted ground Szechuan pepper.
Start with the listed ratio, then scale down if your substitute is paste-like (yuza kosho) or extra fragrant (zest-heavy blends).
If using zest-based swaps, keep zest finely grated and distribute evenly; clumps taste sharper and can turn bitter.
Taste once the dish is warm (not cold) and adjust in small increments—tongue-tingle and citrus read best after heat.
For baking rubs, mix the substitute into dry ingredients so the flavor disperses; for finishing, sprinkle at the end.