Whenever you are knitting and want to widen the shape of your fabric, you need to increase the number of stitches in each row or round. There are a variety of methods to do this, but one I frequently use is the lifted increase.
Before You Begin
Lifted increases are made by working an extra stitch into the stitch that's two rows/rounds below the row/round you are knitting. Adding a stitch this way doesn't create a noticeable hole or bump in your fabric.
Right and Left Slanting Lifted Increases
There is one thing to be aware of when using lifted increases. They do cause your stitches to slant in a specific direction.
See it in Action
If you'd like to make the 'Birch Grove Socks' shown in this tutorial, the pattern is available in my pattern shop.