Not only do Palettes save you time, but they allow you to combine certain functions and actions into automated tasks, speeding up your workflow. Woodgrain Separation can work well with woodgrain on texture files. Download here

The steps performed in the Woodgrain Separation Palette

Starting with a scanned image, black is removed from the image and added to a separate spot layer. The Auto with Create separation function is then used to add five spot layers to the file, using the most prominent colours in the design. Finally, an Advanced Colour separation is performed, using these colours.

How to develop the initial separation achieved using the Woodgrain Separation Palette

The Palette does not fix the Advanced Colour part of the separation so you can open the setting window (Separate Menu > Advanced Colour) and adjust the slider bars, gamma and colour used to fine tune the separation before fixing the layers. 

You could use Combine to Layer to reduce the number of layers in the final design. 

You may also want to recolour the final layers to better match the original artwork.