This ring bag knitting pattern shows you how to make a ring bag from a single garter stitch square.

When I was playing with the garter stitch, I discovered that the edging of the garter stitch is great for picking up stitches evenly as the rows are made easily recognizable by the ridges.
A traditional garter stitch only
I promised to write up the pattern at my Ravelry project page so here it is.
Materials
4 ply sock yarn about 400-450 yards in length
2 small ring handles
Fabric for bag lining
Circular knitting needles – US2 or 2.75mm
The weight of the yarn and size of the needles stated here are what I use for the bag above. They are not carved in stone. You can use any weight yarn and appropriately sized needles to achieve the gauge you want for your bag. I personally like a tight gauge for bags so that they look and feel sturdy.
The body of the bag
Garter stitch is achieved by knitting every row. The body is a knitted square casting on from one of the 4 corners.
Cast on 1 stitch.
Row 1: Knit the cast on stitch.
Row 2: knit 3 stitches into that The body stitch. This is called the Center Double Increase and here is a video showing how it is done.
Row 3: Knit all 3 stitches
Row 4: Knit all and increase 1 stitch at beginning and end of the row. The video above show you how to do 2 increases in 1 stitch, to do only 1 increase, do not do the pick up stitch bit.
You should have 5 stitches on your needles now.
Row 5: Knit all
Row 6: Knit all and increase 1 stitch at beginning and end of the row.
Repeat row 5 and 6 until you have reached the desired size or length of the bag you want. Or slightly less than 50% of the yarn you have. In my case, I used up 200 yards of yarn.

Your knitting should look something like the picture above when you get to midway. A nice triangle.
To make the rest of the body, start decreasing 2 stitches on alternate rows.
Row 1: Knit all
Row 2: Knit all and decrease 1 stitch at beginning and end of the row.
Repeat these 2 rows until you have only 3 stitches left on your needles. Knit the 3 stitches. Turn the work and slip The body stitch, knit 2 together and pass the first stitch over. Cut the yarn and pull it through the loop.
Lining
Line the bag with any fabric you fancy, leaving the edge of the knitted piece for picking up stitches later.

Flaps for bag handles
Pick up stitches from between the garter stitch ridges with the right side facing you (the side without the lining). 1 stitch for each ridge for the entire side.
Row 1: Knit all picked stitches
Row 2: Knit 2 together for the entire row
Row 3: Knit all
Row 4: Knit all
Row 5: Knit all
Row 6: Knit all
Row 7: Knit all
Row 8: Knit all
Flap fold
Row 9: Knit all
Row 10: Purl all
Row 11: Knit all
Row 12: Purl all
Row 13: Knit all
Row 14: Knit all
Row 15: Knit all
Row 16: Knit all
Row 17: Knit all
Row 18: Knit all
Row 19: Knit all
Row 20: *(Knit 1, increase 1), repeat * for entire row
Row 21: Knit all
Bind off
Repeat the whole set of instructions for the opposite side of the bag.
You should end up with 2 flaps that have a fold in the middle folding down over the lined side.
Securing the handles
Place a ring handle on the fold and fold the flap over the ring handle and secure the flap to the bag with some tacking pins. Sew the end of the flap securely to the bag using waste yarn and a sewing needle.
Do the same for the other flap.
Opening of the bag
Pick up stitches starting from the edge of one handle flap to the other flap.
Knit 1 row across. Knit 2 together for next row. Bind off
Repeat for the other side.
Weave in all the ends and your bag is ready for use.
I am sorry I didn’t have pictures of the bag flap and how to pick stitches. I have plans to knit another one using