Here's some tricks for those of you trying to put dummy credits text on the bottom of the poster using Photoshop. Hope this helps some of you! 
::::::::::::::::::::::::: FOR LIGHT-COLORED POSTERS ::::::::::::::::::::::::::
If your poster is light in color, you'll want dark credits text to offset the color. Find a movie poster where the contrast is very high, with very dark text on very light (perfect white is best) background, completely clean, like the picture above.
From your layers palette, select Blending Options --> Multiply, and you'll suddenly see that the white has disappeared, leaving only the dark text. Adjust opacity, brightness and saturation accordingly.
::::::::::::::::::::::::: FOR DARK-COLORED POSTERS ::::::::::::::::::::::::::
If your poster is dark in color, you'll want very light credits to offset the color. Find a poster where contrast is high, but with very bright text on very dark (perfect black is best) background, completely clean, like the picture above.
From your layers palette, select Blending Options --> Screen, and you'll suddenly see that the black has disappeared, leaving only the bright text. Adjust opacity, brightness and saturation accordingly.
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As you can see, it's most effective when you want to place the credits on a very difficult surface pattern to match, such as this one:
