Let’s start with an image.  How about this?

I’ve got the image open in Photoshop, now let’s get a texture file.  I choose 2LO Spirt29

Now let’s put them together.  To do that. I just have to drop the texture file onto the orchid image.

Then move the texture file to fill the image area of the orchid.

You’ll now see two layers displayed on your Layers Tab, one for the orchid image and one for the Texture file.

 

Now we are going to blend them.

First, make sure you have the top Layer, the Texture Layer highlighted.  

Now we are going to adjust the blending of the two Layers.  To do that, select the drop-down box marked Normal and all the possible Blending Options appear.

This next part is where you make the artistic decision on which Layer Blending option to use.

In this case, I choose Screen.  Then I adjusted the opacity on the Texture Layer until it looked the way I wanted.

 And here’s what I got.

The Texture and Orchid blended together well.

BUT,   

I want to add one more step. I want to remove some of the Texture from the Orchid petals.  So, I’m going to use the eraser tool.  The hardness is set to zero. 

Then I just erase away the parts of the Texture I don’t want.   

And here’s what I ended up with.

One other option would be to use the Texture Layer as a Layer mask and paint the Texture in where ever you want it.