A thread chain is a great option for belt or button loops. It's also a great way to create bra strap holders inside garments. One of my favourite things about thread chains is that they easily be easily added to the garment right at the end of sewing (so you don't have to worry about loops and things when you're in the middle of construction).
Here's how to create a thread loop.
1. Cut two long pieces (approx. 70cm) of all purpose thread.
2. Pull both pieces of thread through a needle so it becomes 4 threads.
TIP: It's a good idea (although not essential) to run thread wax along the thread. This will help to stop the threads from knotting.
3. Tie a knot in the end of your threads.
4. Insert the needle where you require the thread chain to begin. You can sew another knot here for security if you would like (before you start sewing your thread chain).
5. Reinsert the needle in the same spot and pull through, but do not pull all the way. Keep that loop!
6. Hold the loop open with two fingers. Hold the thread with the needle in the other hand.
7. Pull the threads with the needle attached through the loop and pull to create a knot and another loop. (This is much more intuitive than it sounds, I promise! ). Effectively you are folding the threads with the needle attached in half to create the loop, which you then pull on.
8. Repeat this step over and over until the thread chain is long enough.
9. Finish by knotting at the end of the thread chain. Usually this means finishing the thread chain in the garment.