Bridge and Camera Raw are programs that ship with Photoshop.
You can access Bridge by clicking on its icon in Photoshop
Bridge is basically a file organizer.
Locate a .jpg photo that will look nice with a simple vignette. (Do not click on it)
I choose a simple snow scene taken outside my door.
We need to activate Camera Raw.
Camera Raw is designed for photos from a camera capable of taking Raw photos.
However, it will also work on flat .jpg photos. (It will NOT work on .psd files)
Right click on your .jpg photo and choose "Open in Camera Raw"
The first screen is the Basic Screen.
If you are in doubt that you're in Basic, click on the Basic icon.
If this is your first time in Camera Raw, adjust the sliders to get an idea of what they do.
FYI: All the adjustments you make in Camera Raw can be re-edited after you leave Camera Raw simply by clicking on your saved photo again in Bridge.
Since I choose a snow photo, I adjusted the exposure and clarity options to really bring out the contrast.
Next, click on the FX icon.
To active the Vignette, you must move the AMOUT slider first.
Then experiment with the other sliders to get the effect you want.
You can go back to the Basic Screen (or any of the other features) simply by clicking on its icon again.
When you are finished, click on this adjustment to set your resolution, color profile, etc.
These are the setting I used:
Then click OPEN IMAGE and your photo will appear in Photoshop.
Here is my finished snow scene with a simple vignette.