How to increase stitches at the end of a row
If you want to shape your knitwear, maybe cast on new stitches at the end of a row for example for sleeves, you work as follows:
Figure 1: Work the row and keep the needle with the stitches in your right hand. Place the working yarn round your left index finger.
Figure 2: Push the right hand needle under both threads.
Figure 3: Pull the needle up, pick up the bottom thread and pull this behind the top thread – see on photo. You now have a new stitch on your right hand needle.
Figure 4: Pull the stitch through with the right hand needle and tighten slightly with the working yarn and slip the stitch off the left hand needle. (Don’t pull too hard or the stitch will be difficult to work in the next row).
Figure 5: Repeat until you have increased the number of stitches according to the pattern.
This way you can cast on new stitches at the end of a row, only using the working yarn.