Couldn't find a vintage Polaroid style that gave results I liked so I made this one.

Krea2 Version
This lora works well anywhere between .5 and 1.0. Just make sure the word "Polaroid" is somewhere in the prompt.

Pony & IL versions:

Works better at higher weights, I find 1.1 to 1.3 works best.

Good Tags to use:
border, realistic, nighttime, outdoors, monochrome, blurry