Problem One: Not having the horse's attention first. Before you ask your horse to do anything be sure it is even listening to you! If the horse is tuned out, you will end up having to use a lot more pressure to get your idea across. I use pre-cues before I make a request, this causes my horse to be aware of the tiniest amount of pressure when I begin to ask him to do something. For an example, when I am not asking my horse to do anything, I keep a very relaxed posture and do not use a lot of eye contact, my pre-cue is to stand up straight, square and look my horse in the eye. If I come to attention as the first step every time before making a request, my horse will learn to follow my lead and come to attention when I do. There are a lot of things you can use as a pre-cue, sometimes I will snap my fingers to get my horse's attention, but a specific word, posture, or gesture will all work as long as it is used consistently before making a request. Being in the habit of preparing your horse to listen and be ready to obey a command will eliminate numerous misunderstandings, and make it possible for your cues to become far more subtle.
Problem Two: Starting with too much pressure. This is different, but related to problem one. As the horse owners were individually tasked to back their horses, time and time again I seen the same thing, they would suddenly begin vigorously shaking or swinging the rope side to side in an attempt to get a quick and respectful response. From the horse's point of view this sudden flurry of motion came out of nowhere, being stunned and confused, they would either stand frozen or try to flee. Because the horse was not responding "correctly" (from the owners point of view) many tried using more pressure to get the idea across, sometimes this would work, when it didn't the owners would often realize that still more pressure was needed, but because they were using so much pressure already, they were reluctant to apply more out of fear of being too harsh, and therefore rendered themselves ineffective. You must be willing to use as much pressure as it takes to get the desired result, but ALWAYS give the horse the option to respond to the lightest possible suggestion first. The starting point for pressure should always be the littlest amount you can use to get your horse's attention and begin making him try to guess what you want him to do.
I challenge all of you to go out and see the smallest wiggle you can put in your rope to make your horse look at you with two eyes. You will probably be surprised how really little that wiggle is. A little softer than that tiny wiggle is the starting point of pressure for your horse, I'm sure you won't feel bad about increasing pressure on him from that point if you should need to. Using this "tiny wiggle test" for each horse, in each new situation is how I find where to start my pressure, then I count: Softest possible pressure 1,2,3,4, Little firmer 1,2,3,4 I mean it! 1,2,3,4 YOU ARE GOING TO DO THIS! 1,2,3,4,5,6,7,8,9. If I find I hold the firmest pressure more than 10 seconds without getting results, I go back down to the "Little firmer" stage without releasing the pressure completely and work my way back up using the same count-it-out method as the first time, with increased intensity. Repeat as necessary.
Of course, perfectly applied pressure is only useful if you have a well timed release. Release on the slightest try, which may just be a shift of the horse's weight in the right direction. If you don't release at the proper time, you are doing nothing more than working really hard at teaching your horse not to listen to you, because you don't make sense.
While this article was written about ground work and backing, the principles of pre-cues and softly, steadily increasing pressure will work in any training situation, including riding.