Hello and welcome to, as the title says, a simple Instructable! This is my attempt at making an easy to follow, and to the point instructable on how to patch jeans.

Step 1: Well Gosh, Looks Like You've Ripped Your Jeans.

This is a rip no bigger than a quarter, but it's unsightly all the same.

Step 2: Cleaning Up the Rip.

Use some small. sharp scissors to clean up the cut (only if it has frayed), cutting out more material to make it even and square is optional but recommended if you want to the patch to look more... artsy.

Step 3: Acquiring Materials for the Patch.

This is where you slaughter an old pair of jeans to make patch material. I happened to have jeans that were 3 inches too small for me all around that were the exact same material as the jeans I wanted to save, so I broke out the scissors and got me a few square feet of patch material.

Step 4: Place the Patch...

Trim the patch to size, a safe size is about two centimeters bigger than your tear on every side. Next, place the patch on the underside of the jeans, and pin it in place with those tiny little pins that old people use to hold dresses in place while sewing them to size.... I've forgotten the name of them.
Side note: It might be a good idea to put on the patch backwards... just seems like it would look cool, i'm not certain though. Try it if you want.

Step 5: Sew on Your Patch.

Im not the best a sewing, so i'm definitely not going to try and give advice about how it should be done, but give it your best shot! You cant butcher it much worse than I did.

Step 6: Add Some Character to Your Patch!

The plain patch doesnt look to amazing, I choose to spruce it up with some thread running vertically along the patch. Assuming this thread wont get wrecked with wearing, it will simply add character to your jeans, and maybe make it look loads more professional or something.