Decorative variation and technical necessity
Twisting a knit or purl stitch is often just a decorative variation of a normal stitch. Using this simple technique borders, structural or woven patterns can take on a surprising effective look. The knit stitches are much clearer and the pattern appears almost three-dimensional.
When it's necessary to increase (sleeves, waistlines etc. or in diagonal patterns) twisted stitches are a good method of working neatly. A stitch picked up from the cross thread and worked twisted does not leave a hole. And stitches which have been increased by wool round needle and then worked twisted leave a smaller hole than normal with this method of increasing. This way you have an easy way of making an impressive effect.

And this is how it goes
When you twist a stitch the stitch from the previous row is turned on its axis to the left.

Knit twist: Put the needle into the back of the loop from the right and knit.	Purl twist: Put the needle into the back of the loop from the left and purl

In our example knit and purl stitches were twisted in both the right-side and wrong-side rows.

Another tip
Twisted stitches produce a very interesting surface - the structure is lively, yet very even.

	In our example the knit stitches (right-side) were twisted and the purl stitches in the (wrong-side row) worked normally.