I agree most of us friendly and willing to help out. I can give you a couple quick pointers. First, sometimes slow is fast. Take your time pulling a cow. Take it easy heading into the herd. Once you have spotted the one you want, point at its hip to make it go forward and head it towards the fence. Use the fence to help control the direction. Pressure at the hip of the cow controls foward motion and speed. If you horse goes ahead of the hip, closer to the cow's head this controls direction or possibly stop.
If you are riding a horse that is cowy and has done this before, trust the horse to put itself where it needs to be to move the cow where it needs to go.
Always try to pull clean, only the cow you want not a bunch, and keep your eye on the back of the head of that cow. Lastly, finish your cow. Just because it is heading in the direction of where it needs to go, sure doesn't mean it will actually go there if you take the pressure off.
Hope all that made sense...