Written in Photoshop CS3.
I wasn't planning on doing a tutorial anytime soon, but since this has been requested a couple of times.. Well, here it is.
#001; First, open an image and crop it. I picked this screencap of LOST, cropped it, and ended up with this.
#002; Most screencaps are quite dark, and this one is too. Duplicate it (right click - duplicate or pressing CTRL + J) and set it on Screen 100%. You may need to lower the opacity or duplicate the Screen layer again depending on your cap. You can of course always edit this later on.
#003; Recently I've really fallen in love with Exclusion layers. I never did before and then suddenly, it was just there. So make a new layer by going to Layer > New Fill Layer > Solid Color and fill it with #3b2307 (or anything darkish brown). Put that layer to Exclusion 100%.
#004; Eek! Where did the contrast go? No worries, that comes back later on. Now we're just going to make a few minor changes now.
I always liked yellowish coloring and have always used it before, so I tried to add that in this coloring too. So, go to Layer > New Adjustment Layer > Color Balance and enter these settings, or whatever you wish, it doesn't really matter. I always go for something red/yellowish, but also trying to get some blue colors in it so it doesn't get too much.
MIDTONES: +25, 0, +15
SHADOWS: +15, +5, -35
HIGHLIGHTS: 0, 0, +15
#005; I think it's a little too reddish now, even with the blue tones in the Color Balance layer. There's a simple way to get rid of that, and that's a simple Fill Layer filled with a light blue (like #defbf7) and put it on Color Burn 100%.
#006; Last step! Just duplicate the base layer, drag it to the top, and put it on Soft Light.
You made it! Hooray!
Comments rock. And results are always cool to see. :)