You don't need to spend hours in Photoshop to make your photos look like the pro's. You can achieve a cool retro effect with just one step. Yup, it's that easy!
Open up your pic. Create a new Adjustment Layer (go to black and white circle icon). Select the Color Fill option and pick a rich shade of blue. Set it to Exclusion with 25-30% Opacity. And you're done. Enjoy your new photo.
(You can play around with the different colors to achieve different looks)