Create a Poke Ball disc by smelting three Apricorns by placing them in a row on the crafting table
Create an iron disc by placing three iron ingots on the crafting table. Alternatively, you can place three aluminum ingots in a row on the crafting table to produce an aluminum disc.
Turn the disc into a lid by placing the disc on a Pixelmon anvil and then hitting the anvil until the disc is a half sphere
Repeat the previous step for the metal disc
Craft a stone button by smelting stone
Place the newly created lid, button and base in the crafting table
Retrieve your new Pokeball
Congrats! You've just made a Pokeball in Pixelmon!