This is my first instructable so let me know how to improve it.
Step 1: Open Up the Picture
First, flip the picture over and bend the top a little bit. a "bulge" will appear and you can tuck the exacto knife under to loosen it. Do this on both sides. You don't have to pull the side flaps up all the way down to lift the top one.
Once you have the side flaps up, use the knife again to carefully dig under the top flap to make that rise.
Squeeze the sides to pop the Polaroid open.
Step 2: Choose a Digital Picture
Step 3: Importing Into Photoshop
The next step is to set up guide lines. If you don't want to make your own, download the Forged Polaroid.psd I have included. Otherwise, there are two ways to manually do this. The first way is to drag down from the rulers (ctrl+R or Apple+R to enable the ruler) to the appropriate lines.
The second (more precise?) way is to go to the menu View and click New Guide. You want guides at the following locations:
Once these guides are in place, paste in the image you want to use and resize it (ctrl+T or apple+T). What you want to be visible should fit to the inside of the guide lines, but be sure to overlap to compensate for alignment errors.
Step 4: Give the Picture the Polaroid Look
Step 1: Image > Adjustments> Hue/Saturation
As you can see, I dropped the saturation about 55. Experiment
Step 2: Image > Adjustments > Photo Filter
Polaroids (mine, at least) usually have a sort of orange tone to them, so I added a rather dense filter onto my picture.
Step 3: Filter > Blur > Gaussian Blur
Consumer Polaroids cameras don't have great focus to them so a tiny blur makes my picture look more "authentic"
Step 4 (optional): Use the blur tool to blur out some of the stuff in the distance. Like I said, Polaroid pictures don't have great focus so stuff in the background may or may not be in focus.
Step 5: Print and Assemble
Flip the Polaroid over and secure the flaps down using glue or tape. Tape is much easier if no one is going to see the back side of the picture.
And now you're done! Experiment and you'll probably have better results than I did.
Step 6: Other Things to Consider..
-Get a better printer
-Use a photoshopped picture of something impossible. No one argues with Polaroids.
-Glue the top side's edges so the image presses to the clear plastic better.