The two pictures below show the 1" X 2" angle trim being applied to the exterior wood trim surrounding a double hung window. The angle trim comes in several different sizes, and can be cut down using a jigsaw or plastic cutting tool shown below.

If the wood that you need to cover is 3 sided rather than just two, then you need to use a combination of small angle pieces on the ends and the larger piece in the middle. In the pictures below, 2 1/4" flat trim was applied to the front section of wood, then 1" X 1.5" Angle trim was applied on each end.

All of the vinyl trim extrusions can be painted to match the house like the piece below. However, keep in mind that the vinyl is maintenence free in it's raw form, but applying paint creates a maintenence issue in the future when the paint fades.