Wanna be warm and snugly when you are reading, staring at a screen, or taking a nap? You need a blanket with a foot pocket. Even if you have never sewed a stitch before, you can make one in less than 30 minutes. Fleece is a great fabric choice because it is soft, durable, almost impossible to stain and will keep your tootsies toasty. You can re-purpose an old fleece throw or blanket. Fleece is available in every possible color and pattern at your fabric store.

ADVICE:

If you have never sewed before, start with a throw rather than a raw piece of fabric.
Probably someone you know has a fleece they don't need. Tell them you want to sew something.
Simple sewing, like this project can be learned in a few minutes. It is easier than driving a car. The satisfaction of making something by hand is a terrific antidote for the unsatisfying parts of modern life.
You can totally sleep under this at night. The satisfaction of making your own blanket has been shown to improve sleep in clinical trials [citation needed].
At your local fabric or craft store, sign up for coupons or a loyalty program to save some real money.

Supplies

A fleece throw OR two yards of fleece from the fabric store. These instructions assume that your piece of fleece is maybe 45-55 inches (115-140 cm) wide and maybe 60-72 inches long (about 150-185 cm).
A yardstick and a marker.
A floor, bed or table on which to spread fabric out on.

AND Some way to join fabric, such as

An ordinary needle and thread. You could use embroidery floss in a nice color.
Any old sewing machine. Go ahead and borrow one. You can learn to sew a straight stitch in about 5 minutes. There are plenty of 'ibles and YouTube videos.
Cutting a fringe along both edges and tie them together. This is not a method I have used for this project, but there are plenty of blankets made this way. Google "No-Sew fleece blanket" and find a nice tutorial. You will need to make the fabric a little wider to allow for the fringe.

Step 1: Lay Out the Fabric and the Mark Cuts.

These instructions assume that your piece of fleece is maybe 45-55 inches (115-140 cm) wide and maybe 60-72 inches long (about 150-185 cm). If yours is bigger that is probably fine. If yours is smaller the foot pocket might be too small for grownup feet.
Fold your piece of fleece in half long ways. If your fabric has a 'wrong' side put that on the outside. The part that is the outside now will be the inside later.
Spread it neatly on a clean floor (or maybe a large table).
At the foot end measure in about 6 inches (15 cm) from where the two corners meet on the short end (away from the fold). Make a small park with a permanent marker in a contrasting color. You could use chalk or some other kind of marker too.
Make another mark 24 inches (60 cm) up the long side (on the loose flaps, not the crease).
Use a yardstick or other straightedge to connect those two marks.
(optional) Use a bowl or a plate to draw circles to round the two bottom corners. Cut off the corners. Admire your work. Put the bowl back before anyone knows what you are up to.
Cut away the triangle, cutting so that the marker wind on the cut-off scrap.

Step 2: Sew It Up and Celebrate Your Awesomeness As a Person.

Sew a line of stitches along the bottom edge from the fold up to the edge of that triangle you cut off. This makes the foot pocket. (More on the sewing below.)
Turn it inside out.
Admire your own cleverness. (DO NOT SKIP!)
Get a nice beverage and go sit somewhere comfortable and put your (shoe-less) feet inside the foot pocket.
Maybe post a picture of your creation. I'd love to see it.