Select the substitute based on your recipe needs—texture, flavor, color, or dietary requirements.
Mix dry starch or flour with vanilla extract (and sugar or turmeric if required) thoroughly before adding to your liquid.
Use the substitute at a 1:1 ratio to custard powder, adjusting sweetness or seasoning as needed.
For arrowroot, add it near the end of cooking to prevent breakdown and ensure proper thickening.
Check the final texture and taste, and adjust vanilla or sweetness accordingly to achieve desired custard characteristics.