Second, the thickness: generally, I will choose heavy fabrics for curtains in bedrooms and rooms facing north, because it can shade the light, facilitate sleeping in, and provide good wind protection, so that the temperature in the bedroom can be higher. If you don't like particularly heavy fabrics, you can choose fabrics with shading coating on the back, which can be lighter and thinner, of course, the warmth effect will be slightly worse.
Third, the size: be sure to check the size yourself when buying. Generally, fabrics with fixed height and width are beautiful when they are only bought at twice the actual size, and 2.5 times is a bit wasteful, which is often referred to as the problem of several times discount, but the shopping guide will generally recommend you to buy them at a discount of 2.5 times. It doesn't matter if you buy a high fixed width, but the width should be at least doubled. Special attention must be paid to wide fabrics (2.5-2.8m). Although the narrow fabric is cheap, it is actually very expensive, and the finished curtain will have seams, which is ugly.
Fourth, decorations: when adding ears, be sure to ask if they can be machine-washed, because many ears with plastic beads can't be machine-washed, and they will fall apart after washing. Another personal experience is that you don't need to add lead drops under the curtain, just leave some money.
Fifth, the problem of washing: Be sure to ask the store whether it can be machine washed. If the shrinkage rate is after washing, it is best to leave more shrinkage space when doing it, so that once the shrinkage is serious, they can let you release the excess. If it is a fabric that can't be washed, it is recommended not to consider it, because dry cleaning curtains are very expensive in square meters.
This is my life experience, I hope I can help you.