Here is a simple way to make wood grain planks or boards. It only uses simple shapes, so no need to worry about any complex drawing. Check out the tutorial section for more illustration tutorials.

Next, I want to draw the planks. I drew five rectangles that are all the same size and line up along the edges. I use the Smart Guides to get the shapes to line up. Go to View > Smart Guides to turn them on. If you are not familiar with the Smart Guides, I have a short tutorial here.

After you’ve drawn the planks, you want to arrange them behind the ovals. The reason for this is to maintain the colors of the ovals when you use the Pathfinder tools in the next step.

To use the Divide Pathfinder, select all the shapes and click on the Divide button.

The Divide Pathfinder cuts up your shapes into smaller individual pieces.

After the Divide, all your objects are grouped together. To ungroup them, go to Object > Ungroup. You may need to ungroup several times to separate all the objects.

Now that your objects are ungrouped, use the Selection Tool to delete the unwanted pieces along the edges.

Next, separate the individual planks. You may want to rearrange, flip or rotate your planks to so that the ovals don’t line up anymore.

Here is the wood texture that I created in action. I used it to create a pirate ship deck.