A lady at my church wanted me to put a pillow together for her. It's made from a sweatshirt she wanted to give as a gift, and it was seriously Easy Peasy.
First cut out your front and back. I just lined it up using my ruler and marking it with a disappearing ink pen. Cut it out. You could do it with scissors too. I cut both out at the same time to simplify things, but you can do it with any fabric cut separately as long as they're the same size.
Flip so right sides are together. They didn't line up perfectly, so I just trimmed one edge. No big deal.
Pin edges. You won't sew between the two purple pins on one side. This leaves an opening for stuffing and turning the pillow. Just leave enough open to stick your hand through. This was probably 3" or so.
Clip edges. This is so there's less bulk at the corners and you get a sharper point.
Turn your pillow right sides out. Your corners might look like this, but I just stuck a pin in there and picked the corner out.
Ready to stuff. Put as much batting in as you want. I stuff little bits into the corners first.
After it's all stuffed, you'll have one open side.
Pinch the opening together like so. Pin, then slip stitch it closed. This stitch is so you cant see it. There's all sorts of tutorials online for this. It definitely takes a little practice, but it's really easy once you've done it . Don't be scared.
The finished seam all closed. Not perfect, but you can't even tell really.
And that's it. Super easy and fast. Totally washable too. You could make one of these out of a kid's favorite blankey, a favorite piece of clothing, some cute fabric or whatever.