Hi Carla, you can buy valance clips for vertical blinds. This great video that will show you how to install them - https://www.youtube.com/watch?v=EKgf4_Jak0Y
Hi ! Years ago I saw what someone did in their home and I thought it was clever , and it might work for you . They put up a small shelf over most of the Windows in her home . She just put up 2 smaller brackets and attached a piece of wood . Then she attached a curtain of valence to it , plus it gives you storage ! In her kids room she put stuffed animals up there . In the kitchen she had baskets , in the bathroom she had some greenery ....