Note: If you don't have a neck warmer to copy over, you can draw all the pieces by hand. For better measurements, use your child's t-shirt. It is not important to be very precise in this project, so don't worry.
For this project you will need a very little fleece and a velcro not more than 1.5 sq.cm in size.
Here are all the parts: the largest U-like shape on the left is the front piece, two on the bottom left are the back, the long rectangle is the neck part and two little rectangles serve to straighten the velcro area at the back.
When I put all the pieces together, the project will become more clear:
And this is what the pieces look like once cut in fleece (sorry the long rectangle is missing, but will show up again below :)):
Start by stitching the top two corners of the front and back pieces, where the shoulders are:
Next, fold the largest rectangle in half. This will be covering the neck, so you need to attach it to the front and back. For a more smooth look, use the zig-zag stitch that will firmly hold two pieces in place.
Here it is when finished:
Now attach the two little rectangles: the bigger one on the left back piece and the smaller on the right back piece. Fold them over the edge like in the picture below, and stitch through.
After that, stitch the bottom lower back. The back will finally become a single piece.
The neck warmer is almost done. Now you just need to stitch the velcro at the back.
And you're done! Congratulate your self.
Here is the front:
And here is the back:
Now our two neck warmers look almost the same. Can you tell which one we just made?
You guessed it, the one on the right. :) Happy sewing.