Match your recipe type: for spreads/sandwiches, choose something with zest/peel; for glazes/sauces, choose citrus jam + adjust acidity.
Start with the ratio from the table above (or the listed WPRM ingredients) and stir well to distribute zest/peel evenly.
If your substitute is smoother than marmalade, mix in lime zest (or finely chopped peel) to recreate the rind texture.
Taste and balance: add lime juice for tang, a pinch of sugar for sweetness, or a tiny pinch of salt to sharpen citrus.
Use immediately for best flavor, or warm gently for glazes until it loosens and blends into the sauce.