A granny square is worked in rounds. Working in rounds is a little bit different from working in rows, though you use the same basic stitches for both. When I say "working in rounds" I am talking about where you start in the middle and your piece grows outward, getting larger, until it is the size you need. This is a very good method to use if you need a square to be a particular size or if you plan to use different colors and have only a small amount of each. You can always adjust up or down with a granny. You can usually get within a half inch of the size you need and then add a round of single crochet to bring it up to size. Size may be important if you are making a square for a charity, for example, and it is to be joined with other squares of the same size.
There are two kinds of grannies you might hear mentioned if you do a lot of charity work:
Granny's daughter - one round of the basic granny square which will be four 3dc shells and 4 ch spaces. I usually use an H hook and worsted weight acrylic yarn. To see if I have enough yarn, I wrap yarn loosely around a 12" ruler 7 times. Don't stretch it. Just loosely wind around the length of the ruler.
Saltine - two rounds of the basic granny square. If I can wrap worsted weight yarn loosely around a 12" ruler 16 times, I find I have enough to make a saltine.
There are at least four different ways to begin a granny (or any project worked in the round).
Method 1 - Make a slip knot, ch 5 and join with a slip stitch working first round into the ring (as shown in the other tutorial) Method 2 - Use the alternative to the slip knot, ch 5, and join with a slst as in method 1 (see video below) Method 3 - Start with an adjustable ring Method 4 - Make a slip knot, ch 5 and work your first round into the first chain
It doesn’t matter which way you use, but if you are making squares you are going to join together, it might be a good idea to use the same method for all of them, just for continuity sake.
Most granny squares are meant to be worked on the "right" side, without turning. However, some people like to turn their grannies, thus making them "reversible" in a sense. This may also help if you are having a problem with your granny lying flat. Sometimes just that little bit of difference will help.
When it comes time to join the rounds of your granny square, know that there are several methods for doing that. Here are a few, just so you know about them.
Slip stitch in top chain of beginning ch3, then slip stitch in next two dc and in next ch-3 space, ch 3 to start your next round, continue to work corner in that same space.
Join first round with a dc, ch 3 and begin next round corner in same space, working around the dc just made. Join succeeding rounds with a sc or hdc.
Ch 1, hdc in top chain of beginning ch 3, then work first shell of next round in same space. Succeeding round are done the same way except on my final round I usually chain 3 and finish with the invisible finish off.