The simplest ones are wooden beads made from elder or willow.
Cut off a branch as thick as your middle finger, cut it into short lengths and poke out the centre pithy core. Depending on how much work you do to these hollow tubes, you can make some beautiful beads.
Usually I take the bark off and then soak the beads in dyestuff. The willow bark boiled up will make a dye that will darken the wood. If you add some rust from iron, it'll make an almost black dye.
Wayland decorates wood with carved designs, and then colour contrasts those.
Tiny cowrie shells can be bored and threaded onto fine cordage.
Leather pieces can be dampened and designs stamped on.
Claws, tusks and feathers can be tied and pitched over the cord to secure them.
Antler and bone both carve well and have been used for millenia.
Some trees have bark that carves very well, indeed I have a beautiful leaf pendant that Neil-1 made from bark. It's lightweight and smooth and a favourite of mine
We know of raw copper and gold that was just beaten into flat sheets and then coiled up into cone shapes, these were stitched onto clothing or made into earrings. Not much raw copper or gold lying around now though.
Have fun
cheers,
M