Here are some photos my assistant and we did this after I was fiddling around with using flash during the day. Once again, the speedlight is behind her with an orange gel to mimic the sun. This technique can be used to amplify golden hour. One thing though: the hair type of your subject will impact how you utilize and off camera flash. If my subject had straight hair, I likely would have moved my light to a different angle. Thankfully, she has curly hair, which looks even better when I put the flash directly behind her.
One other quick tip, if you want to up the quality of your result, then do your first round of processing and then go do something else for 10 minutes. Then come back and do another round of processing. Every time I do this, I find that my first round was just off in some way or another and usually the quality of my end results jumps after I take that quick break after the first round of processing. The fresh eyes really helps.