To make Double Treble Rows in crochet begin with a foundation chain of any number of stitches + 3.
Row 1: 1 DTR in 5th. ch from hook (4 skipped ch stand for 1st. stitch),1 DTR in each ch to end, turn.
Row 2: 4 CH ( to stand for 1st st.), skip first dtr,1 DTR in each dtr,ending 1 DTR in 4th. of 4 ch, turn.
Repeat row 2.