You can experiment by comparing modern things with traditional. Compare
spruce roots with nylon. Compare bone with plastic.
You can experiment by comparing one thing with another. Compare a down
coat with a fur coat. Compare nets of different colors. An experiment is
nothing more than a fair test.
Finding out information on your project from elders and other sources is good, but you must interact with that information. Test it. Compare it. Try new ideas. Try different materials. Try at different times or seasons.
The judges will be looking for a project that involves the scientific method. If you understand this, you will score high. (I know because I wrote their score sheet.)
Back to the list of suggestions.