Twirl Wood Texture in Photoshop

Create a new layer in Photoshop by going to File> new and fill it with a light brownish, slightly orange color by using photobucket tool. Try different colours depending on the type of wood grain you want to create.

Goto Filter->Noise->Add Noise and add some noise with the following settings.

Then select the duplicated layer and goto Filter->Artistic->Poster Edges. Use the default settings.
Now the wood is starting to look somewhat realistic, but its not quite a there yet. The problem is that the photoshoped wood is too perfect (more noticable with a larger sized picture). Real wood has knots, wane and other irregularities in it.

Goto Filter->Liquify

The best way I have found to create the knots with the liquify filter is to take the following steps

1. Select the spot to create the knot
2. Use the nudger tool to create push out the wood texture on both sides of the spot you selected
3. Then use the spiral tool in a slight up down motion to create a realistic knot.

Then you should have your result, a nice realistic wood texture