And you'll need:
Seed Beads: purple and green colors;
Jewelry Wire;
Green embroidery floss to wrap the wire;
Foam as the base for the tree;
Glue;
Decorative tree.
First twist 4 wires to get 4 branches in a "cross" shape and around the axis, start string beads, then gradually form a beaded dome... Wanna learn more details? See here. Happy crafting!