This is for the kind of clasps you find for capes and cloaks like here:
Which are difficult to simply sew on "button style".
To attach these you will need the following tools and supplies:
Your choice of clasp
Headpin to match, you can choose either a "flat head" headpin or a decorative headpin. You can find these online or in the jewelry section of your craft store (or even WalMart). They are typically in the jewelry making section for making earrings.
Crimps with a gauge large enough to accommodate the headpin. Most standard crimps and standard headpins are made to work together.
Crimp tool (see pictured)
Wire cutters (to cut off the excess part of the headpin)
Extra fabric (to sew over the back of the headpins and crimps) or crimp backs - the purpose here is the same, to make sure after crimping the back and cutting the excess headpin, you provide some sort of protection so the rough wire isn't against your skin
Step 1: Step 1 Place the Headpin Through the Clasp Hole and Fabric
Position the clasp on the fabric to make sure that the loop or the hook overhangs from the fabric edge so that it can close.
If your fabric is a loose weave, you may want to put a thicker fabric on the back to stabilize it such as a soft leather.
As you push the headpin through the fabric, make sure the fabric is straight and tight against the back of the clasp, to prevent it slipping.
Step 2: Step 2: Push the Crimp Down on the Headpin, All the Way to the Base
It is very important that there is as little distance between the crimp when you clamp it down and the top of the headpin as possible when you crimp it. Otherwise, you will have a long headpin securing and it will "sag" under the weight, eventually ripping your fabric.
If you accidentally do this, do not worry! Just take your wire cutters you are using to cut the excess part of the headpins off, cut between the crimp and the headpin and then start over. You usually have 2-3 extra headpins per package for a few oopsies.
To do it right, hold one finger securing the top flat part of the headpin against the front decorative part of the cloak clasp. Pinch this and the fabric together on the back, (see picture) Then, using the nail of your thumb, hold the crumb tightly as far down to the base as you can. Now, you can use the other hand to use the crimping tool and clamp down on the crimp.
Clamping down on the crimp will cause the metal crimp to collapse.
Step 3: Step 3: Continue to Crimp the Rest of the Headpins in Place
As you can see, once the metal crimp has been collapsed with your metal crimping tool the fabric no longer travels up and down the headpin. Go ahead and insert the other headpins and crimp them one at a time.
Step 4: Step 4: Cut Off the Excess Headpin
Using the wirecutter, cut just above the crimp you have collapsed, taking off the excess wire from the headpin.
Step 5: Step 5: Cover the Sharp Parts on the Inside
Now it is secured, but you'll have a sharp metal poking you if you don't cover it with something. I recommend soft leather sewn over it, or just a patch of the same cloak or cape material. However, you can find "crimp covers" which are metal covers that will also provide some comfort through places like firemountaingems.com