The most usual styles are either machined with tape heading or handmade with hand pleating, but there are many variations and styles within each theme.
They can be sill length, full length or over long to 'puddle' on the floor. A pelmet or valance can be added but with careful consideration to proportion as they can be overbearing and reduce light.
Contrast edges, braids and trims can all be included for definition, to embellish a plain curtain or a way to reuse or update existing curtains. Dress curtains (sometimes called 'false') are an alternative if you want to give a finishing touch to a window but would not need to draw them. These work very well with a roman blind or with a pelmet or valance fitted above.