How do you form a double treble crochet stitch?

First, make a chain that is three stitches longer than the number of double crochets you want in your row.

Bring yarn once over hook from the back to front; skip the first three chains from the hook, then insert the hook into the 4th chain. Hook yarn and draw it through the chain stitch into the working area of your hook. You now have three loops. Hook yarn and draw through the first 2 loops on the hook. You have two loops. Hook yarn. Draw yarn through both loops. When you reach the end of the row, make three chains before turning to start the next row. This chain three counts as the first double crochet of the row.