what you need:

For this tutorial I will be using size 10 needles and a chunky, single ply yarn so that you can better see the stitches.

making a slip knot:

Make a pretzel-shaped knot and put your needle through it (the point in this picture is at the bottom left).  Then pull tight:

the thumb method:

My grandma taught me how to cast on in a really easy way — with your thumb!  Hold your needle in your right hand and use your left to make the loops you’ll need.  Hold the working yarn with your pinky and ring finger.  Make a rotating motion with your wrist to quickly and easily make a loop around your thumb:

Now you’re going to take the needle and insert it under the loop, like so:

Now remove your thumb from the equation and pull your loop to the needle (but don’t pull it too tight — you’ll need to be able to work into these later):

Now repeat the whole loop-making process with your thumb until you have enough stitches on the needle for your project (I have 14 here):

Yay!  You’ve cast on!  Some patterns call for a specific kind of cast on (there are a zillion ways to do this), but I find this to be the easiest way when it doesn’t matter how you do it.  And now you’re ready to knit or purl!