Here is how I join in the round for magic loop! The 3 tips are: 1- Place a marker after you have casted on half the stitches plus 1 (which will get subtracted later) The marker will help you be able to pull out the loop of the cable. 2- Straighten your stitches before trying to join them in the round. Then pinch the ends together to keep the orientation correct. 3- Slide the first stitch to the back before starting and then at the end of the round make the second to last stitch go over the last