(From Clare's article archives, Circa 2010-2015)
This is a relatively easy issue as well.
When your horse balks, or stops and won't go forward, turning them is the best remedy.
Usually, trying to use a steady, constant pull on the leadrope (imagine that stubborn donkey in the movies), just makes your 4 legged friend dig their heels in further.
But...if you pull towards the side, you can most of always get your horse to go forward. Sometimes a tug and release, tug and release, in a straight line will work, but the best, sure fire way to get those hooves moving is by pulling them off to the side to get the feet moving, and then back onto the desired path.
Repeat as necessary.
There are 2 other common ways to get your horse to go forward from behind, when you ask, or to go faster if you want them to.
1. Use a whip, or the end of the lead rope, to send your horse forward from behind.
If you are on your horse's left side, this is done by guiding them forward with your left hand on the leadrope (you will be looking at your horse and standing at their shoulder), and with your right hand holding the end of the rope or a whip,
swooshing the horse forward from their hind end.
2. The other method is accomplished, again if you are on your horse's left side, by controlling the motion of your horse with your right hand on the rope, looking forward where your horse is going, and using your left hand back behind you, toward the horse's hind end,
with a whip or the end of the leadrope.
This technique is much easier to demonstrate visually with the video, then to describe with words, but is very effective for increasing a horses forward pace.