How does everyone make hi-res "realistic" tracks?

How do people like hoppingicon make their realistic tracks? Also, how can I use them without having to struggle with the 25MB limit?

1) PaintNET is the software that most of the best track creators use if that helps at all ^^ As for how to use it to make good tracks, well I've never actually used it so idk
2) The 25MB image limit is only for the images that are hosted directly on MKPC, so you can just upload the track image to an image hosting site and copy the link ^^ Recommend Postimages for anything smaller than 800x800, and Imgbb for anything larger

I don't know sorry