Creating tileable textures

Today I learned the process of how to create a seamless texture using a standard image. Here is how I did:

This is the original texture I found on the internet for a scratched up metal. 

Here I cropped my texture to a 1024x1024 square.

I offset the original square, blending the edges using content aware fill and healing brush.

And here is my texture tiled a couple times! Not all that great, but it doesn't have any harsh edges that would be obvious in the game engine.