There is really nothing new in the shape of knife and dagger blades that haven't been made sometime in the past 2,000 years or more. For a Traditional looking knife, avoid using materials that didn't exist during the time frame in issue.
A. Don't use Stainless steels for blades.
B. Don't use synthetic materials for handles or hilts.
C. Avoid using metals that were not available- like Aluminum-- back when.
Most handles on working knives were made of wood, but some were made from bone- not always antlers. Fancy knives for Royal customers got the full treatment- silver, Gold, Platinum, engraving, Ivory or Ebony or other exotic woods, etc.
Folding knives were single blade affairs, not the multiple bladed "Swiss"-type pocket knives we know today, with all the extra tools enclosed. Some whale bone, baleen, tusks, and other forms of bone or ivory were seen in knives made by sailor during the whale hunting period prior to the Civil War. But, for the most part, working knives were simple in construction and function.
Few knives were made to be used in Knife fights- with double guards or hilts. Short swords were popular among the richer classes along the coasts, replaced by pistols and revolvers as the century progressed, during the early 19th century, but rarely seen out in the wilderness.
From a practical perspective, the longer you use knives to do a variety of work, the shorter the blades become. I use my pocket knife more to gut deer than I have my "sportsman's" knives, either folding or fixed blades, for instance. The bigger blades simply get in the way and are hard to maneuver inside the carcass where you want to cut the windpipe loose to free the lungs. Skinning chores can benefit from a longer blade, however,so there is no ONE knife- shape or style or length-- that does everything well. Knives were the original "all-purpose" tool, that never was expected to do everything well.
That's as close to defining Traditional knives as I can get for you. " I know it when I see it", is about as good a definition( Thank you, Justice Potter Stewart).