I love making granny square scarves but anytime I make make a project easier I will! Here, instead of making single granny squares, I've started with a single crochet type chain the length I wanted the scarf.
I didn't count my stitches, though you're supposed to. That would have driven me crazy. I made a triple treble at the end to make my corners. Now I only have to stop to change colors or skeins. This one I'm only using one color but the next one I'll choose a couple. I had to make sure I could figure it out first.
I trebled into every third stitch down the chain with 1 stitch in between each treble. By the way, a treble is 3 double crochet done into one stitch. I made a triple treble at the opposite end and did the same down the other side making sure to treble into the same stitches as before. This makes the center look nice and neat.
Make your scarf as wide as you like. I'm probably adding a scallop row to finish.