Make It: Easy Crochet Slip Stitch Blanket - Tutorial (It may seem crazy, but simply by repeating the slip stitch over and over you can produce a thick and dense crochet fabric. I have found it is especially great for making scarves for men.
If it's pouring outside, why not take up some needles and yarn and make this lovely Rainy Day Washcloth. If you know how to knit a dishcloth, you'll have no trouble crafting this simple washcloth. With a bumpy texture, this easy washcloth is great