First, you need a straight stick. Not a crooked one that looks like it survived a tornado; I mean dead-nuts straight. Grab a dried sapling or a piece of hardwood like ash, birch, or hazel. Pro tip: A green branch will warp faster than your grandma’s bingo night luck.
Strip the bark off with a knife or a piece of broken glass (responsibly, you maniac). Then, heat the shaft over a fire and gently bend it to straighten any kinks. You want it so straight that if you rolled it down a hill, it would boast about its perfect posture.