With this technique you create extra stitches to shape your knitting. There are several methods, which have variations depending on which row you are working on, and which direction the increased stitches need to slope in to create the effect you want. Your pattern will specify which method to use.
MAKE ONE LEFT ON A KNIT ROW
This method is usually abbreviated as “m1” or “m1l”—if a pattern just says “m1,” this is the increase it refers to. It creates an extra stitch almost invisibly.
1. From the front, slip the tip of the left-hand needle under the horizontal strand of yarn running between the last stitch on the right-hand needle and the first stitch on the left-hand needle.
2. Put the right-hand needle knitwise into the back of the loop formed by the picked-up strand and knit the loop in the same way you would knit a stitch, but through the back loop (see page 41. You have increased by one stitch.