The make 1 (also known as the lifted make 1) is an easy and very tidy looking increase. It utilizes the running thread between two live stitches to create a new stitch. This increase can lean to the left or to the right depending on which direction you pick up the new stitch. Instructions for both are provided below.
To slant left: Lift the horizontal thread between your needles with your left needle tip from front to back. Knit this newly lifted stitch through the back loop.
To slant right: Lift the horizontal thread between your needles with your left needle tip from back to front. Knit this newly lifted stitch.