Kite base
The kite base is the simplest traditional starting shape: a square with two neighboring edges folded to a diagonal crease, so it looks like a kite.
Turn the square so it sits as a diamond, fold it in half along one diagonal and open it again. Then fold two edges that share a corner inward so they lie exactly along that crease. The result is a long, symmetrical kite with a broad end and a sharp point. Many simple animals, fish and flower stems begin this way.
The usual mistake is letting the folded edges overlap or leave a gap along the center crease, which makes the kite lopsided. Hold each edge on the crease along its whole length before pressing, starting at the sharp point. On this site the Fish and the Tulip Stem both open with a kite base.