Depending on your sewing skills, patience and time, it may take a few hours to a day (or more).
If any extra help is needed or there's confusion in a step, please leave a comment or leave a message.
Step 1: What You Need
Step 2: Step One: Measurements and Cutting
Therefore, I've cut out 24cm x 18 cm rectangles of cloth.
Tip: it's pretty useful to iron the pieces of material before cutting them. It also results in a cleaner and neater finish.
Step 3: Step Two: Decorating
For this pencilcase I have chosen to use ribbons and beads to decorate.
If you are using beads, use chalk to mark out the spacing between each bead.
If you are using robbon, rule out a line using a ruler and chalk to make sure you sew it on straight.
Do not forget to leave enought space around the sides if you are using beads or anything else where your design will be sewn inside.
Step 4: Step Three: Preparing to Sew the Zip
Arrange the pieces of materials and use pins to hold them in place. Then do a basic stitch to attach the pieces. This is to ensure the pieces don't slide out when sewing using the sewing machine.
Refer to the notes on the image to see my setup. In my case, I used two pieces of white cloth. You can use as little or as many as you like. Although if you're already using canvas/upholstery material, it isn't necessary.
Step 5: Step Four: Sewing the Zip
Sew one side of the zip. Sew the zip on opened. Keep this in mind: the foot of the sewing machine might need to be changed to one that's for sewing zips on, especially if the zip is buldgy.
Now sew on the other side!
Step 6: Step Five: Sewing the Bottom of the Pencilcase
Step 7: Step Six: Sewing Up the Other Sides
Turn the pencilcase inside out. If the inner layers are showing, adjust the stitches/pins/just sew over it.