Trees can be made by a simple vertical line with horizontal lines squiggled on top of it that starts wider at the base and get increasingly smaller toward the top. Landmarks to determine a starting point and a finishing point (the treasure spot), and landmarks to help the hunters find their way in the middle.This is probably the most important feature! After all, pirates aren't known as being great artists! Include things like:

X Research source The features don't have to be perfect. Feel free to use different colored inks you can also use colored pencils, Sharpies, or watercolor paint. If your character can't carry the treasure alone, have your companion share the burden.Draw specific features on your map. Just tell them to stay put, give them all your item and explore the place to seek the treasure. when you got to the treasure site, remember to have companion with you. raise your luck so that the treasure is worth more than you pay for it. Just equip it and it will either show the hidden place of the treasure or show that the map is fake (just like in CoAS) when you got offer to buy a map, buy it and check if it's genuine. save in the tavern when you got in so that you may reload if the treasure map is fake. If what Ben Coats said is true, then there is a chance that we may got cheated with a fake treasure map, so remember to do these thing if you are going treasure hunt Also you may encounter a group of treasure seekers trying to rob you after you get out of the cave. So it's recommended to have a companion to help carry them.

And depend on your luck, the treasure may contain a lot of valuable stuff that your character may not be able to carry them all. So the swords and candle are just random object that spawned in the cave. I finally found the treasure, and it worth a lot more than the money i had paid for it.

Treasure maps on pirates caribbean hunt