You might find that this is really. hard. sometimes. Below are some of the issues I ran into when I first starting sewing leather, presented with frustration intact. (And some solutions)

I can't pull the needle through!! WTF??

There are two things you can do to fix this:

Use an awl to punch through the holes again. Leather tends to close up over time, so those holes you punched won't be as open as they were when you first punched them. Just take the leather, lay it on a piece of cardboard, and use the awl to reopen the holes. Grab a pair of pliers! Sometimes it can be so hard to grip the needle with your fingers with enough force to get it through. Using pliers to grip the needle in one hand and bracing the leather with the other can absolutely help. This will also help when backstitching.

The holes in my leather look AWFUL after pulling thread through them, WHY?!

Chances are your leather is super dry. The friction from the thread can cause the holes to look a little shredded sometimes - the flesh can flake and get fuzzy. If you find this happening, apply some jojoba oil (or whatever you prefer!) to the stitching holes.

My stitching looks wavy and terrible - WHAT HAVE I DONE?!

If you find yourself with wonky stitching, chances are is was an issue with the holes you punched or the way you sewed the leather together.

Make sure that when you're punching holes, you're doing in in a stitching groove or you've used a stitching spacer to get a nice straight line.

Also, if using an awl - make sure your holes go straight through and the skinny edges of the awl's hole are at a 45 degree angle. If you're punching holes and the skinny edges go horizontally, you're holding it wrong. Click here for more information.

If it's not an issue with the holes you made, it could be your stitching:

Be consistent. Always bring one needle through the holes first, and have the second follow behind. Always pull the thread tight after every stitch. Don't puncture your already stitched areas with your needle - always try to keep the needle going into the holes next to the thread - not through it.