This is just a very simple Photoshop tutorial. I’m using this icon.

Open any image that you want to put borders on. If the layer is locked, double-click it to unlock. If the image has layers, press Ctrl + Shift + E to merge them. This technique won’t work if you don’t merge the layers.

Go to Edit, then Stroke. The width, which is in pixels is dependent on how big or small your image is. For the icon, I chose 5 px with the color white. Make sure the location is set to inside. It now looks like this.

Do the same thing, only that the width is lesser than the first, or your first stroke won’t be seen. I set mine to 1 px with the color green to match the icon. Tada! Now, you’re done.

I added a simple text, and here’s my final result.