A clean curtains makes a bigger difference than you'd think. Here's the most effective method, plus the mistakes most people make.
Read the care label to determine if curtains are machine washable, hand wash only, or dry clean only.
Vacuum curtains while still hanging using the upholstery attachment. This removes dust without taking them down.
If machine washable, remove from the rod, shake out, and wash on cold gentle cycle with mild detergent.
Hang curtains while still slightly damp to prevent wrinkles. Avoid the dryer for most fabrics.
Iron or steam curtains while still slightly damp for a smooth finish.