Instructables
This is a pretty easy bag to make for a holiday gift.
It only has a lot of steps because I documented each item for ease.  It goes pretty quickly. Once you make one, you will realize how easy it is.  Make a bunch..  for friends as cosmetics cases, a small catch-all for inside your purse, or make longer for kids as pencil cases.  Upholstery or fabric shops often have beautiful remnant pieces for a song.  Experiment with different sizes. 
 
 
Remove these adsRemove these ads by Signing Up

Step 1: Requirements:

Picture of Requirements:
Fabric piece (at least 12" x 18")
Zipper
Thread
Needle
Pins
Ruler or straight edge (to mark)
Sewing machine

Step 2: Cut and iron

Picture of Cut and iron
Cut your fabric in half lengthwise.  On the longest side.
Iron edges under 5/8" for zipper placement.

Step 3: Pin in zipper

Picture of Pin in zipper
Pin or baste zipper in place.  Sew in zipper.  No worries, a long zipper can always be cut down to size. 

Step 4: Zipper inserted

Picture of Zipper inserted
Zipper inserted.

Step 5: Sew opposite seam.

Picture of Sew opposite seam.
With the zipper closed, and the right sides of the fabric facing eath other, sew the side opposite the zipper closed.  It now looks like an open tube of material with a zipper on one side.  Here is a photo from a different fabric, but it is the side I am pointing to.   

Step 6: Sew ends

Picture of Sew ends
Lay the fabric tube with the partially OPEN zipper facing up.  (Open because I learned the hard way.)  Sew the two remaining sides closed.  You can sew over plastic zippers (slowly), but jump over any metal pieces. 

Step 7: Mark corners

Picture of Mark corners
This is a bit hard to explain, but hopefully the photo will demonstrate the seams to sew now. Holding the bag with the zipper facing up, (like a box of Kleenex) mark and pin in 1" - 2" on the corners.  These seams run parallel to the zipper and give the bag its height.  If the bag comes out too short, increase the length of the seams as you sew in closer to the zipper.

Step 8: Seams sewn

Picture of Seams sewn
This is a photo of all the corner seams sewn.  Trim corners and excess of zipper if needed.

Step 9: Ta Daaa

Picture of Ta Daaa
Turn inside out.
Add a little ribbon on to the zipper to decorate.
Ta Da.  A pretty zippered case for a holiday gift.