This is my new favourite crochet stitch:
Start with a foundation chain of whatever length you require - my square is 32 chains long.
Do a double crochet in the second chain from the hook, 1 chain, *double crochet missing a stitch in the foundation chain, 1 chain repeat from * to the end of the foundation chain.
*1 chain, double crochet in the chain space of the previous row, repeat from * to final chain space, 1 chain, double crochet in the chain at the start of the previous row.
Repeat the row until the piece is the length you require.