Start by applying a gradient to the background layer.



Create a triangular shape using polygon shape tool.



Double click the layer to open layer style window. Apply settings as shown.









Duplicate the layer. Right click the layer and select rotate 180°. Double click the layer to open layer style window. Change shadow angle in inner shadow. Move the layer to the other site.



Create a triangular shape using polygon shape tool.

Double click the layer to open layer style window. Apply settings as shown.







Duplicate the layer several times and place as shown.



Type link or menu  names below the triangular shape layers.



Create a rectangle using rectangular shape tool. Place as shown. Create an arrow shape using custom shape tool. Place it above the rectangle layer as shown.



Duplicate both the layers. Duplicate the layer. Press Ctrl+T. Right click and select Flip Horizontal and place on the other side.



Insert company logo in the middle of the header.