Learning how to decrease stitches in knitting is very easy! It's as simple as knitting two stitches together to create one stitch. Here's how it's done.
Step 1: Starting with the working yarn in back, insert the tip of the right hand needle into the 2 stitches you will be knitting together. The tip enters the stitches from bottom to top and the right hand needle will be behind the left.
Step 2: Bring the working yarn forward between the needles.
Step 3: Swoop downward with the right hand tip, catching and drawing the working yarn through both stitches, and sliding the combined stitch off the needle.
One stitch decreased.