Step 1 - Quick before & after
Let's take us back to the oldern times when films and photos looked like the above. It's actually kinda nice looking in my opinion. What i'll be showing you to do is gradient maps, and a few filter effects. After the hard work, the photo will turn out just like the one on the right in the above sample.
Click to enlarge
Step 2 - Regular Picture & Naming
Alright, for this tutorial you'll want to be very organized so you don't get lost. Start off by finding the photo you want to test this effect on. After you have it, create a new document and throw it in there. Now duplicate that layer and name it Gradient. Name the original layer Background.
Step 3 - Gradient Map
Once you have the two layers organized, select the layer Gradient. Now go up to the top of the Photoshop window and find Image > Adjustments > Gradient Map. Click the black & white gradient and a new window will pop up. Now find the one that says Violet, Green, Orange once you roll over it. Use that and then click OK. Refer to the image above by clicking it.
Step 4 - Film Grain
Alright, yes the image might look a little weird right now. We're working on making it look better, so don't fool around with the other settings just yet. Use the same layer and go to Filters > Artistic > Film Grain. Then use the settings in the image or below:
Highlight area: 2
Then click OK.
Step 5 - Lowering opacity
Alright, now time to fool around with the layer's opacity. Go to the Gradient layer and lower the opacity to anywhere around 50% or until satisfied. The one in the image above is set to 50%. I kept the blending mode Normal, but you can explore with it and change to overlay or whatever you wish. I'm sure you can get a better result!
Congratulations, your finished! Here's a copy of the .psd file. Enjoy!