Any soft, supple worsted weight yarn will work great for this. A stiffer worsted weight yarn will not drape well.

This pattern is worked form the shoulders down. The back panel is crocheted first, then right and left front panels. The panels are joined with side seams, leaving openings for arms. Worked almost entirely in double crochet, it makes a basic-yet-pretty fabric that works up fairly quickly. Also, makes the perfect base for adding things like flowers or buttons on to personalize.

To make this pattern larger, I would start by measuring your shoulders across the back and then making your initial chain that long, then following the rest of the pattern through. You also may want to make the straps in front start wider. In this case, you would just start the increases a little further down to line up with the increases on the original pattern.