First, make a loop so that the part with the end of the string lies over the bottom part. The end of the string is under my index finger.
Now, pull the other end up and over the string going to the end and through the hole in the middle. If done correctly, you should be able to pull the loop made in the middle
of the other loop to tighten it.
If you've truly made a slip knot, you should be able to pull on the long end of the
string and the knot will get smaller. If you pull all the way, the knot will come out totally. Now insert the safety pin into the loop made.
The string is now ready to be put in the channel. Take a look at the back of the bag where the tabs are.
This is a seam and stringing the bag will go much easier if the safety pin goes through it correctly. Feel the seam to see which side of the line feels thick. The thinner side is which side you want to put the safety pin through first.
On the cloud bag shown in the pictures, the thinner side is on the right of the vertical line (er, seam) so I will insert the safety pin and go from left to right. Insert the safety pin with the string attached into the button hole.
Start gathering the fabric along the channel by
pinching the string with your left hand, and sliding the safety pin along the channel.
fabric will start to gather. About 2 or 3 times, pinch the safety pin instead of the string and
pull on the bag itself with the left hand.
Eventually the safety pin will show up at the buttonhole where you started. Make sure to hang on to the other end, or you'll pull on the safety pin and it will all go through and you'll have to start over. In this picture, I have both the safety pin and the other end in my hand.
Once the safety pin is through, unlock it and take off the loop. Pull on that end of the string to undo the slip knot.
Tie the ends together. Repeat the whole process on the other buttonhole. Make sure to remember which way you slid the safety pin (either from left to right or right to left) and it will go easily. Now you are done!