You will need:

Size 1 ½ needles (I use two needles from a set of double points with point protectors on the ends)
A variety of leftover sock yarn (or some new sock yarn!!)

Cast on 31 stitches. Turn.
(I know you know how to cast on, but I wanted you to see a photo of the needles with the point protector.   I also use a 1 1/2" small circular needle ordered from www.paradisefibers.net
Row 1: Knit all stitches. Turn.
Row 2: Knit 14 stitches. Double decrease as follows: Insert R needle into 2 stitches as if to knit them together but instead slip BOTH stitches simultaneously over to the right needle. Knit the next stitch, and simultaneously pass both slipped stitches over the knit stitch and off of the R needle. This decreases the row by 2 stitches and leaves the center on top. Knit the last 14 stitches. Turn. (29 stitches)

Row 3: Knit 14 stitches. Purl the middle stitch. Knit 14 stitches.  Turn.
Row 4: Knit 13 stitches. Double decrease as in Row 2. Knit 13 stitches. Turn (27 stitches)
Row 5: Knit 13 stitches. Purl the middle stitch. Knit 13 stitches. Turn.
Row 6: Knit 12 stitches. Double decrease as in Row 2. Knit 12 stitches. Turn. (25 stitches)
Row 7: Knit 12 stitches. Purl the middle stitch. Knit 12 stitches.  Turn.

By now you can see a pattern. You are only doing the double decrease on the right side rows. When you have only 3 stitches left on the needle, just do the double decrease. This will leave 1 stitch on the needle. Cut the yarn and pull the loose tail through the loop on needle. You have one square completed.

Joining the squares:

Place two squares side by side as shown:

Pick up and knit 15 stitches from the square on the right .....


and 15 stitches from the square on the left. (Note: There are only 30 stitches on the needle at this point.)Turn
Knit the first 15 stitches on the needle. Then make 1 with the yarn that is connecting the two squares. To make one I just picked up the yarn that is between the two squares and gave it a twist and put it on the left needle. This stitch should end up on your left needle because you need to knit it to keep on going. Then knit the last 15 stitches. Total 31. Turn.  (You can also do the make 1 as you are picking up the stitches.)

Note: You only have to do the make 1 part on this base row of squares. After you get the row joined together, you will pick up a stitch in the center of the square that is in the row below.

You should be on the front of your work and ready for a decrease row. Do this square the same as you did the individual squares.