Apply a Sepia Tone to a Photo in Photoshop

Here's How:

1. Open the image in Photoshop.
2. If the image is in color, go to Image > Adjust > Desaturate and skip to step 4.
3. If the image is in grayscale go to Image > Mode > RGB Color.
4. Go to Image > Adjust > Variations.
5. Move the Fine<-->Coarse slider down one notch less than the middle.
6. Click on More Yellow once.
7. Click on More Red once.
8. Click OK.

Tips:

1. Use the Save... button in the Variations dialog to save the sepia tone settings. The next time you want to use it, just load the saved settings.
2. Use Desaturate and experiment with Variations to apply other color tints to your photos.