Choose a size for your square. 6 inches by 6 inches (15x15cm) is small enough to be quick and easy, and big enough to keep you going. However, any size will work.
Choose how wide you'd like your blanket to be, and work out how many squares you will need to make one row.
Knit some squares, and be careful to get them exactly the right size - if you don't it can be hard to avoid bunching and misaligned squares. Sew them all together in a row using mattress stitch or similar. (Tutorial here on Knitty.)
Continue to knit more squares, and when you have the second row stitch it on to the first.
Keep doing this until the blanket is as long as you'd like it to be.
- Although you can use any yarn and any stitch, if you want a cuddly item then chunkier yarn works better because it makes a warmer blanket.
- You can experiment with aligning the "grain" in alternating directions.
- It looks better if you don't have a "reverse" side - so stockinette stitch is not so good.