An exercise: imitation of wood in a plastic piece of 4x4 cms.

Mark the strips and the wood grain.

A first layer of light brown color as a primer. (oil-based color)

Second layer, very thin with the darkest brown.

From here, alternate paint, increasingly dark, with a light sanding. (paper)

The same, again.

Paint applied unevenly, to appear light-dark wood.

Final sanding pass with tissue.

Faux finished. Now you can spend some dry brush to tone of aging.

Regards, Xavier