You may have hit part of the nail on the head with the standard jaws on the Nor Vise perhaps not being your best option. I too use a Nor for a lot of my tying. I also have the luxury, (or something else) to have many different vises. Nor does sell a set of midge jaws for your vise. These will help in a couple of ways. What may be the least obvious is simply one of scale, and how very small those larger jaws are making the hook appear. Size 20 and smaller are really small to begin with. The much smaller jaws will help as a matter of perception. You will find that the smaller jaws will immediately make you feel more comfortable or less intimidated by the small size of the hook. The larger jaws can also limit your ease of access to the hook when tying.
Magnification has also been mentioned as well as GOOD lighting. You can't tie what you can't see.
Also, another great suggestion of starting with a larger size anytime you tie a new pattern, and tying several (6-12) of that size, going to the next smaller size and so on. The next thing you know you will be amazed at what you are able to tie.
Unlike some tiers who answer the challenge of "how small can I really tie this" (sz 32 for example) I rarely tie below a size 24. But, you can miss a lot of good fish between 20 and 24. So get the jaws, get the magnification, and get the light.
OK, got all that stuff?
Now get tying and in the next couple of months post a picture of a size 24 on here (or smaller) of a fly consisting of more than just thread. I'd really like to see your fly attached to a nice fish!
You can do this, and I can't wait to see your picture (s).
Tight lines,
George