Today, around lunch time, I took my dog down to the park to throw his ball for him. When we arrived there was a guy working on casting a fly rod. I watched him for a minute and it was obvious he had no idea what he was doing so I asked him if he'd like some help. He jumped at that chance, so I told him after I let the dog pee on some bushes I'd come back and work with him.
The first thing I did was put about 2/3 of his line back on the reel. I explained to him when you work on learning how to do basic casts you need to use less line. He was making the same mistake most new people make in that he wasn't picking the line up off the ground hard enough to start his back cast, then he wasn't using enough muscle on his forward cast to load the rod and get the line shooting out ahead. I demonstrated what he needed to do for a bit, and explained everything I was doing, and why, then handed the rod back to him so he could try.
After a few casts he started do a little better and he was encouraged by that. I went over behind him and grabbed his hand as he held the rod, and "helped" him cast and he really stared doing well. I moved back to the side and he started getting every cast down well. After a bit he stopped and turned to me with a big smile on his face and said, "I have NEVER cast this good!" I told him to just keep doing what he was doing and took the dog down the line to chuck his ball for him, leaving behind me a fly fisherman with a whole lot happier outlook on life.