Everybody longes a bit differently so if you do it another way and it works for you, please carry on. This is the way I was taught; it works for me and my horses. That being said, a few safety points: Never loop the extra longe line and hold it with your hand through the loop. If the horse gets away from you, it will tighten around your hand and you will be going to the hospital. Similarly, do not ever let the loose end lay on the ground where it could wrap around your legs in a tangle. Again, horse takes off and you just scored a broken leg. Instead make big accordion type loops and hold the entire accordion in your hand. The longe line will feed easily out of your hand and you won't get caught if your horse gets silly.
The idea is to form a triangle with your body and your horse. I hold the extra line and the whip in the hand towards the hindquarters. The other arm is outstretched in the direction of travel, and is the signal for "go." My focus is on the hindquarters -- especially when I'm asking for more. So one arm is part of a "V" towards Winston's face and the other arm is part of the "V" towards his hind. He closes the triangle with his body. Here's a short video of us starting out. You can hear me saying "aaaanndd T-rot" in the first section. He is getting much better at making prompt transitions off of my voice from walk to trot. In the second section, you can see him get a little silly when I ask for the first canter. This is as crazy as he gets. I ignore the antics and we just keep going.
Winston is not as prompt with the other transitions. He gets trot-canter promptly about 50% of the time which is a big improvement over where we started. Canter down to trot is good, but he's clueless on trot to walk. You can see it takes him awhile to get that one in this next clip.
We worked quite a bit on transitions. Winston made his work harder by transitioning from canter to trot when it had not been requested. When he did that, I put him immediately back to canter and he had to complete a full 20m circle without breaking into trot on his own. Once he completed the full circle, I let him trot. You can see that in the last video clip. I've also asked Brett to put a couple more holes in the side reins. Right now they are on the last hole and are still too long to help him with contact. Now that we have the basics of longeing commands and etiquette down, he needs to work with contact.
My foot has been feeling much better this week -- not nearly as fatigued and achy at night. I'm hoping to step up the number of days that I longe him. Right now, I've only been able to manage two per week -- each with a couple recovery days on the couch in between.