Basic Pillow Cover
What you’ll need |
piece of fabric, (w"+2") x (2l"+5")
Matching all-purpose thread
sewing machine
colored pencil 
measuring tape/ yardstick
pair of scissors

* w = pillow width; l = pillow length

Approximate time |
You should be able to complete this in 2 hours or less.

1 Measure the length, l, and width, w of the pillow to be covered. If you don't have any old throw pillows to cover, you can buy pillow forms (uncovered pillows) at any fabric or craft store.
fig. 1 >

3 Wash the fabric to pre-shrink, then cut to size.

4 Finish the short sides of the fabric by folding the frayed edge over 1/4", then folding the fabric again (approximately another 3/4"). Sew with a straight stitch.

< fig. 3

5 Place the fabric on a flat surface such that the outside of the fabric is showing. Fold the fabric as pictured below (fig. 4). It doesn't really matter where exactly you make the folds, although I like to have the first fold larger than the second, so that the cover opening will be near the bottom of the pillow. The important thing is to make sure that the distance between folds is exactly the same as the length of the pillow.

  fig. 4 

6 Stitch both sides shut, using a straight stitch, and leaving a margin of 1" along the edges (fig. 5).  7Then finish the frayed edges by folding them over approximately 1/4", and using a zigzag stitch (fig. 6). 8 Flip the cover right-side out, and slide in your pillow. Voila! You're done.

^ fig. 5 ^ fig. 6

VARIATION: Velcro-Closure Pillow Cover
If your pillow is a very fat pillow, the simple envelope-style pillow cover described before may not work so well (your pillow innards will constantly be threatening to bust out). The easiest way to secure the cover shut is using velcro. In addition to the materials listed for the basic pillow cover, you'll need a strip of velcro (both loop-side and fuzzy side, of course) that's approximately (w"-4") in length.

1 Follow steps 1-4 for the simple pillow cover.
2 Place the fabric with the inside of the fabric facing up. Approximately 3/4" from the top of the fabric, lay down one of the velcro strips and sew the strip securely into place. Fold the fabric as pictured below:

3 Mark the placement for the second velcro strip using a colored pencil. Sew the strip securely into place, using a straight stitch to go around the edges:

4 Fasten the velcro strips together, then flip the fabric inside-out. Proceed to sew the edges, as instructed in steps 6-8 of the basic pillow cover instructions.

VARIATION: Button-Closure Pillow Cover
A nice alternative to the velcro-closure (which isn't so much pretty as it is functional), is to use buttons to close the pillow cover. You'll want at least 2-3 buttons, depending upon how large your pillow is, to secure the opening shut. Follow the same instructions as for the basic pillow cover. At the end, though, you'll need to sew on your buttons, and create buttons holes (this is the slightly tricky part).

2 Thread your needle, doubling over the thread and tying a large knot at the bottom. Holding the fabric with the right-side facing you, bring the needle from the back of the fabric through to the front, inserting it approximately 1/4" in from the opening in the fabric, as pictured in figure 2.  < fig. 2

3 Having pulled the thread through, your needle should now be coming out the front of the fabric. Insert the needle back through the fabric, going front to back this time. Now here's the important part: as you bring your needle through the fabric, you'll want to make sure that it goes THROUGH the looped part of the thread, as pictured in figure three. 
 fig. 3 >

4 Got it? Good. Now continue using this same stitching pattern until you've gone all the way around the perimeter of the button hole.