Reddit mentions: The best safety mirrors

I'd really, really rely on getting this effect through the lens rather than in post.

Do you or any friends have a go-pro? That'll do it.

...or if you can't afford a GoPro/lens, just get a fisheye mirror and film your subject through the mirror.

https://www.amazon.com/PLX18-Circular-Acrylic-Security-Diameter/dp/B0009HK8FG/ref=sr_1_4?ie=UTF8&qid=1483339603&sr=8-4&keywords=fisheye+mirror

If you can't afford that, change your location to the Grocery store, have your talent stand under the big aisle mirrors that are in 90% of grocery stores, and film it at that angle with a telephoto.

Get creative! That's the joy of film-making.

Put a small mirror above your computer monitor. I put mine so that it's at the edge of my peripheral vision, so that people walking behind me don't grab my attention, but someone just standing at my cubicle will. I've found it to be incredibly helpful when I have my headphones on, but someone still wants my attention anyways.

I've seen driveways like this have giant round mirrors that allow you to see incoming traffic, and also allow the incoming traffic to see you.

Here is an example: https://www.amazon.com/Circular-Acrylic-Outdoor-Convex-Security/dp/B005C6BSZS

Solar light like this and a convex mirror

I've got one of those hospital mirror balls for corners. I've had it for like 20yrs on my desk.