Identify your recipe type: dry baking (cake/brownies), thick batter (frosting), or a liquid sauce/marinade.
Match texture needs: if the recipe uses espresso powder dry, prefer a powder-form substitute (instant espresso/coffee) rather than brewed coffee.
Use the listed ratio as your starting point; then adjust for bitterness—add a touch more only if the flavor tastes flat after mixing.
If your substitute is liquid (brewed coffee), reduce other liquids slightly so the final batter/sauce consistency stays the same.
For ground-coffee swaps, mix thoroughly and strain if you need a smooth finish.