Identify what your recipe relies on: moisture absorption (quick breads), fiber chew (muffins/breads), or binding (loafs).
Replace wheat bran using the listed ratio, then mix thoroughly to fully wet any bran-like particles.
Let the batter rest 5–10 minutes (especially for flax or psyllium) before baking or cooking.
If batter looks dry, add 1–2 teaspoons of water/milk at a time; if it looks too thick, loosen with a splash of liquid.
Bake/cook as directed, then adjust next time: add less substitute if the crumb gets gummy, or add a bit more if it’s too dry.