You can spend hours trying different textures and changing the colour of your image so here's just one way that illustrates how textures can be used.
Step 1: Go black and white
Open your image up in Photoshop, duplicate it and convert it to black & white (Image>Adjustments>Black & White). We want to give this image a slight blue tint which is added by ticking the tint box and moving the Hue slider to the chosen colour.
Step 2: Add your texture
Textures can be anything from a shot of cracks in a wall to wood and Hessian. What works and what doesn't depends on the photograph you're using so it's always worth experimenting with a few different ones before completing your image. For this tutorial we're using a close up shot of wood found on a pier. To add it to your photograph simply select the Move Tool, Click and hold the mouse button down on your texture and drag it over to the photo.
Step 3: Adjust the texture
If the texture is too big, small or not quite in the right place you can adjust it by going to Edit>Free Transform. This will put a box with anchor points around the texture you can move until it fits.
Step 4: Change the Layer Blend Mode
When you're happy with the texture's location change the blend mode from Normal to Overlay. This will blend the texture with the original image.
Step 5: Paint detail back
The texture's in place but it overlaps part of the scene such as the wooden boards which doesn't look right. To remove it we are going to create a Layer Mask by clicking the Layer Mask icon at the bottom of the Layers Palette. Select the Paintbrush Tool, making sure black is your foreground colour, and paint over the areas you want to remove the texture from. Once this is done that's basically all there is to adding a texture to an image. If you want to give the image more mood you can adjust the brightness/contrast of the texture and/or the original image. How much you do this by is up to you and will also change from photo to photo.