Once I learned this trick, I had to go slap myself. Seriously. Ignore my earlier post about this topic because this one is much better.
Let’s get started.
Once you have your photo or video adequately sized and placed, you do this.
Add the Drop Shadow effect from the Effects Panel to the clip you want a border around.
First, change your shadow color to what you want. I picked yellow. Then make the Direction 0, and make the Opacity 100%. Finally, change the distance to something like 10.
Now copy and paste that drop shadow effect three times. So you should have four drop shadow effects.
Next, change the Direction in each of the effects to 0, 90, 180, and 270.
Here’s a screenshot that shows the settings for each effect.
Once you get this effect stack set up, you can save it as a preset. And use it in so many different ways.
I also made a video tutorial walking you through the steps and added more information about how versatile this can be for adding a border to your clips in Premiere Pro.