When joining knitting in the round, it’s imperative that the work is not twisted (unless it’s a desired effect). I thought I’d share a little tip on how to easily make sure that you can follow that “making sure cast on stitches are not twisted” direction. (For purposes of this demo I’ve knit a few extra rows.)
This is the correct configuration before joining the work:
4in 300dpi Joining_in_the_Round0001

1. Lay the circular needle on a flat surface
2. Make sure the entire cast on edge i.e. β€œthe bottom” is pointing into the centre of the circle
3. You are now ready to join the two ends and start knitting in the round

This is What NOT to do:

4in 300dpi Joining_in_the_Round0002

Although the beginning and the end of the cast on edge are pointing into the middle of the circle, notice that there is a twist about half-way around (at the bottom of the photo). Although this would work for a funky circular scarf, it’s not so good if you’re knitting a sweater or skirt.