I love using different cross-processing techniques... in Photoshop, but most tutorials insist you use a Curves adjustment layer. Unfortunately Photoshop Elements users don't have this in their toolbox. I wrote a cross-processing action that uses curves that works in PSE, but unless you have the action, you PSE users can't do this on your own.
So the simple solution? Use a Levels adjustment layer of course!
Here is an image. You might recognize this image, I have used it a hundred times on my blog because I am lazy. :-)
Add a Levels adjustment layer.
There are 4 channels; RGB, Red, Green, Blue. I selected the Red one first. I adjusted the Output levels on the bottom and also the input levels via the sliders. I can't give you exact numbers, you have to play for each image.
Now I pulled down the Blue channel and adjusted the Input and Output levels. Again, I just played until I liked the color effect.
I usually don't use the Green Channel that much, but it can give a lovely reddish effect so be sure to check it out. You can adjust one color channel or all three. Finally, I adjusted the RGB Input levels to add a bit of contrast pop. If you want to add haze just move the Output black slider to the right.
Isn't this a fun tip? Don't be afraid to play, you can get all types of color effects using Levels. Yes, a single adjustment layer. Funny, you probably just thought you could only adjust lightness/darkness/midtones!
If you have any questions, please post them them in my CoffeeShop Flickr Group!