That would depend on the decor. If feminine, use white sheers, if rustic or masculine maybe woven blinds.

Lace curtains are always a nice choice - particularly if you can find old lace or tea-dye it to look vintage. Get on Pinterest and look at lace curtain pictures. You will see a lot of simple styles that might give you an idea what you are drawn too. You could do the same with blinds and roman shades.