Twig & some craft foam? That is all I can think of, We have some kind of tree, never gets to big about 10-12 ft at most that has 1/2 in or some larger little miniature pine cone looking things. Might be able to group them together for a more lifelike looking tree. would have to glue or wire together & paint green & attach to thick piece of twig. Could you use some of those cone shells,tree snails,olive shells or wentletrap shells. I don't know anything about shells except I like them. I looked in the dictionary on the shell page. Some are quite common & can be gotten at craft stores. ,If you wired 5 together would look like the top or a palm tree- they are long & some spiral,a lot are small so would work in a jar.

Dollar Trees always seem to have palm tree type stuff. I wonder if they have a miniature type something you could take apart.

Another idea would be to print out a tiny photo of a palm tree. You could cut it out to look like a postcard.

Or you could make a dough tree base and stick tiny artifical fern fronds into it.

I've made little palm trees using Sculpy and adding fronds made from silk plant leaves, trimmed and cut to look like palm fronds and a wire glued to the back of the frond so I could shape them.

Turned out cute!! Jan

Years ago my grandmother had some palm trees made from chenille stems bumpy green ones for the fronds and brown ones for the trunk. I don't have any pics. or pattern but it shouldn't be to hard to figure them out.