After a recent photo shoot, some people asked how I was able to achieve a certain sepia look with some of the images. As a reference point, here is the original image:
Connor Baker 2x3 ratio
I then opened the image using the Nik Silver Efex Pro 2 plug-in for Photoshop. I applied one of the presets called "#36 Antique Plate":

With a few final tweaks in Photoshop, here's the final result:
Connor Baker 2x3 ratio (sepia version)