I chose six "Buffy" caps at random from Dead In the Scene. Their original size is 1024x768.
1. After opening some caps in Photoshop, I make a new file (File > New). The size of the new file depends on how many caps I am doing and in what configuration. For this tutorial I am doing three caps across and two down, so the size of the new file is 3072x1536 pixels. Usually my picspams are 3 across and 6 down, so there is 18 caps per file.
2. I pull one of the caps up and duplicate it. Set the top layer to "Screen" and sharpen (Filter > Sharpen > Sharpen). Merge the two layers together (Ctrl+E) then paste it into the new file you just made.
3. Open "Curves" (Layer > New Adjustment Layer > Curves) and adjust to your liking. I used RGB (I:131, O:188), Red (I:126, O:136), Green (I:124, O:133), Blue (I:129, O:153).
(note. "Buffy" has a lot of yellows and reds, in shows with more blues and greens like "Supernatural" or "Battlestar Galactica" the blue curve layer wouldn't be so high. You should fiddle around and see what looks best with the caps you are using.)
4. Open "Hue/Saturation" (Layer > New Adjustment Layer > Hue/Saturation) and adjust to your liking. I used Master (+10), Greens (+25), Cyans (+31), Blues (+29).
5. Pull one of the next cap and duplicate it. Set the top layer to "Screen" and sharpen. Insert it between the "Curves" and "Layer 1".
6. Repeat step 5 until your file is full.
(note. cap #6 is bright on it's own, so I didn't duplicate and screen it before adding it to the file.)
7. Resize the file to a width of 600 pixels. If there are any gaps in between your caps adjust them so none of the white background layer is visible.
8. Finished product:
Tip: If you want the coloring to stay consistent, resize the file to it's original size then delete the old caps, and insert new caps in between the background layer and "Curves" layer.
See the Layers!