I am going to show you how to create a burnt/melted poloroid in photoshop.
First download this image
Now take that photo and make it black and white by going to Image>>Adjustments>>desaturate
Now go to image>>adjustments>>levels and mess with the settings to give your picture a more old look. Then add noise by going to filter>>noise>>add noise and use similar settings to this
Now we are done with the photo for now.
Start a new document about 400X400px with a white background. Start a new layer and draw a white square about the size of the canvas leaving room on all sides.
Add a grayish innerglow so you can see the shape
Now use your rectangle marqee tool to cut it out and make it look like a poloroid picture.
In a new layer below that one create a black rectangle behind it to cover up the cut out.
Now that you did that drag your image we adjusted into this document and fit it in the image above the black shape and leave some of the black shape showing around the edges.
Highlight all of your layers except for the background layer then duplicate them. After that merge the 3 layers together and hide the other 3. I am doing this to have a backup in case I mess up.
Hit ctrl+t on your keyboard to use the transform tool on the image and then pick the warp tool to warp some of the sides and edges like this
Next grab your burn tool from your tools, set it to highlight, and choose a 65px soft
brush. Burn around the edges and on the actual picture
Ok now I want to erase some parts of the image to make it look like it has parts of it burned off so grab this eraser brush
Erase some spots around the image like this
Use your burn tool again to burn around the parts of the picture we just did
Time to add some melting. Create a new layer above that one and then hold down ctrl and click on the little icon beside the previous layer to make an outline of our image.
Now choose a grayish brown color for your foreground color and white as your background color. The color I used is #d4caaf.
Then go to filter>>render>>clouds
Then go to filter>>artistic>>plastic wrap with these settings
Then go to filter>>sketch>>chrome with these settings
Keep trying the plastic wrap and chrome filters a few times until you get your desired result.
After that set the layer to pin light and erase some of the melting from around the edges
Duplicate that same layer for added effect.
Here is my result
Now duplicate your main layer and drag it above all the others and set it to saturation for more effect on the melting.
Now for a final touch I want to add some burnt orange and yellow burnt marks to the image. When you burn a poloroid it starts turning a yellowish and reddish color.
So grab a 27px soft brush and get a dark orange color and go around the photo on certain areas
Now grab a greenish color and do the same thing
Set that layer to color burn and you are done!