Take a look at the video I linked to or watch others on YouTube and see if you can figure out where it's going wrong. You might also try the cable cast on on a swatch.
For the srist warmers, you'll want to cast on the stitches onto the needle that has the working yarn coming off the end. This is the needle in your right hand. You'll take it into your left hand to do the cast on and once you have the 4 sts cast on, the needle goes back to your rigth hand and you continue knitting to the end of the row.