This is the newest Pittsburgh Steeler (color) afghan that I made. It's VERY simple. Below are the instructions. No, the pattern is not mine, it comes from BERNAT yarn.
I used crochet hook size H
Chain 280 sts (you can make this shorter or longer, but your stitches must be in multiples of 7)
Row 1: 1 dc in 3rd ch from hook, 2 dc in next ch, *skip 3 ch, 1 sc in next ch, ch 3, 1 dc in each of next 3 ch, repeat from * to last 4 ch, skip 3 ch, 1 sc in last ch. TURN.
Row 2: Ch 3 (counts as 1 dc), 2 dc in first sc, *skip 3 dc, 1 sc in first ch of ch-3, ch 3, 1 dc in each of next 2 ch, 1 dc in next sc, repeat from * ending skip 2 dc, 1 sc in top of turning chain. TURN.
Repeat Row 2 until afghan is as large as you want it.
Border: For the border, I simply did sc stitches on both sides to make it look "pretty". I began and ended the afghan with black so that I only put a black border on each side. I did 3 sc in each turning chain, and 1 sc in the next "stitch" (alternating).