I made this bag out of a thrifted leather jacket 2 years ago (and didn't think to post it till now!) I won't show you the lining because after two years of carrying it every day, it has taken quite a beating... Seriously, every day. It fits my laptop so I used it as a bookbag in grad school.
I didn't get a great picture of the strap, but it's braided and very cute. The pockets are from the original jacket, and they're quite useful for holding all the doodads I carry around. The leather is so buttery soft and rich. All for under $10! Yay for up-cycling!
Thanks for looking!
So a lot of people were asking for tips to make their own, so I thought I'd add them here. Also, I've replaced the lining since I posted this, so basically I'll be using this bag forever...
I sewed it on a regular machine with heavy duty thread. I used a regular needle for this one, but I recommend a needle specifically made for leather because the stitching looks nicer and it's healthier for your sewing machine.
The way a regular needle works on fabric is it pushes fibers aside to pull the thread into the weave, and then the weave holds the thread in place. Leather isn't made up of fibers, it's all one mass, so the needle needs extra pressure to bore through and make a hole in the leather. Needles made for leather have a little blade at the tip, which cuts a tiny slit in the leather so that the needle doesn't have to bore through. It makes the stitches look more even and nice too.
Whatever needle you're using, remember to use a longer stitch length. When you sew on fabric, you can take out stitches if you make a mistake and the weave smoothes out over the "holes," right? But with leather, once the needle goes through, that hole is permanent. Now, if your stitches are close together, the seam is going to be weak because as soon as you have something heavy in your bag, that seam is going to rip from hole to hole like toilet paper. If the holes are farther apart, the seam is stronger.
If you want to try making one, but you don't want to buy a leather needle, just make your design so that it doesn't have any top-stitching (so all of the seams would be right sides together and hidden inside). Top stitching looks awful if you don't have a leather needle and heavy duty thread. Also, if you're using a regular needle, don't try to go through too many layers at once (you'll break the needle, or worse, your machine). On this bag, I hand sewed the part where the strap connects to the bag because there were so many layers of leather, lining, interfacing, and zipper, I wouldn't have been able to do it on the machine.
Another tip: Iron your seams! It looks so much more professional. Of course, this applies to all sewing! Just be careful with your iron settings so you don't damage the finish on the leather. Test on scraps first, and maybe iron through a cotton cloth to be safe.