The hook used has a long straight shank and a smaller head than regular hooks.
The hook at the top is the Prym 1.50mm Crotat hook and the hook at the bottom is a regular Tulip 1.50mm hook. You can see the way the head on the Crotat hook is smaller and inline with the shank. This to make it easier for the head to pass through the stitches.
Prym produces these hooks in 1.00mm, 1.50mm and 2.00mm which are all suitable for use with up to a size 10 thread. If you would like to make something with thicker thread or yarn, you can either use a wooden or a bamboo hook.
Having used both, I prefer bamboo. It may take a little longer to work the hook in and make it slippery enough for the stitches to slide comfortably along the hook but it is stronger and more supple than the wood. They also go down to a 2.00mm size and I now prefer my bamboo hook to my metal one.
You will find it easier to use either the bamboo or wooden hooks if you make a slight adjustment to the heads.
Using a fine grade sand paper, sand either side of the head so that it is slightly narrower than the main shank.
Some of these hooks have quite a sharp tip. Rounding that slightly will stop the point hurting when it hits your finger – and it will hit your finger no matter how careful you are!
Then, fold the paper and use the folded edge to deepen the grooves. This will encourage the yarn to sit in the grooves.
Sanding the lip of the hook will help stop it catching as you attempt to pull the yarn through the loops.