This is my steps on how I add a texture layer to my photos using Photoshop CS3. Note: these steps should work for Photoshop elements. I am not sure about other photo editing programs though.
Before I apply my texture I do all my other post processing first. The only thing I leave for after the texture is resizing for the web, web sharpen and adding my watermark.
This is the photo I am adding a texture to:
First step is to have your photo you want to apply the texture to and the texture you wish to use open.
Here I am using a texture by Ghostbones. You can find them HERE
Next you will need to drag the texture layer onto the photo using the move tool (highlighted with the red circle). Note: If you use another photo editing program you should have a similar tool. As you can see I need to resize the texture layer to fit my photo. You may or may not have to do this with you photo and texture. To resize the texture layer I just grab the bottom corner and drag with the mouse for it to fit my photo.
Here you will see my texture layer resized to fit the photo. It completely covers the photo from edge to edge. You may need to move the texture around to make sure it covers the whole photo.
Now the fun begins. Making sure your texture layer (layer 1) is selected you can tell this by the gray highlighting. Go to the layer blending and change that to Soft Light. You can choose the others to see which suits what effect you are after. I use Soft Light the most. The others I tend to use are Overlay and Multiply. You can also change the opacity of the layer if you think the texture is too much. Another thing I might do is use a layer mask and mask the flowers for a lesser effect of the texture on the flowers or whatever my subject might be. If you have no idea what a layer mask is let me know and I can try to write a tutorial about how it works.
That is pretty much it once you get the texture the way you want it and keep in mind you can do these steps to add more texture layers. In the past I have used 2-3 different texture layers.
The final thing to do is merge your layers.
And the finished photo:
There are no doubt numerous other tutorials out there but these are my steps. So you may come across other tutorials that use different methods.
Please let me know if you found this tutorial useful or if you have any questions.