Creating an U-shaped clip connection

In such cases, the best practice is to use a stiffening member operation and find a suitable cross-section that can be edited to a proper shape. 

Then you have to change the cross-section according to the following pictures. This type of cross-section can be then easily transformed into a bent plate.

The following video shows how to place the element and connect it to other joint parts.

Other possibilities are importing it from a 3D CAD drawing or composing it using stiffening plate operations.