Help! How can I create this effect?

I would be grateful if anyone could tell me how I go about creating the following effect.

It's hard to be very specific about the look I want to achieve, but I would describe it as a grungey, weathered effect. This is probably best illustrated with examples, one being a texture applied to an old journal on the homepage of the Style-Force site at http://www.style-force.net/1894.htm, and another being a texture applied to a poster used on one of the official sites for the movie Once Upon A Time in Mexico, found at http://www.terra.es/cine/elmexicano/index2.htm.

I am pretty inexperienced with Photoshop and confused about how to create such an effect, so any help would be appreciated. Thanks in advance.

I'm a photshop profesional, and i can tell you simply, for exactly that look... Take a photo! I guarentee that the 'once upon in mexico' folded up paper is exactly that : a folded up paper photo. And over that they stuck another photo of another 'grungy' texture they grabbed somewhere, and set that leyer to an effect like multiply.

Building up a good texture bank is a great advantage to graphic design, you should look into it.

Basically just remember to have your main item on the bottom layer (like the photo of the paper), and find some interesting textures to stick over it and set the layer to things like overlay, multiply etc... And play with the opacity if needed.

I hope you weren't looking for a "filters" way to achieve this effect, because quite simply, filters are mathematical, and its hard to make math look natural and dirty. They tend to look repetitive. A photo texture is really the best and quickest way for you.

hope that helps some, experiment!

Thanks for the advice Wakorobro.

try scaning in some crumpled/folded (and the straightened out) pieces of paper. turn these scans into brushes. There are also alot of good sites with brushes similar to that look. try a search for them. look here