It depends on the color of the fabric you wish to starch. Boiled cornstarch and water works well, but it needs to be made in small batches to prevent spoilage, and may show as white streaks on darker-colored clothing. Vodka and water won't give you as stiff of a fabric, but it also won't show on darker clothing, unless you have very hard water. In that case, use distilled water, rather than tap.