You have to remember that the golf swing mentioned is far different when you are stuck in a sand trap because there is something blocking your way and you have to go over that. To do that, you have to hit the sand behind the ball using the club head. How far will the ball travel depends on the distance between the club head and the sand.
In both instances, a good golfer must be able to adapt with the surroundings and the weather. If the winds are strong, you cannot hit the ball at 7.5 or 12 degrees every time. The rule of thumb is that when the wind is coming from behind you, you have to use a club that has a greater lie angle. If the wind is coming to you from the front, you should use a club with a smaller lie angle. If you do not follow these rules, the ball will not travel far or you may end up with a slice or a hook.
Making the proper golf swing is not easy. If that was the case, almost everyone will be able to hit a hole in one. This is why professionals practice more than 8 hours a day because they know that there are things beyond their control and the weather is a very significant factor.
Now that you know what to do, it is just a matter of practice so you can put theory into practice. If you are still having a hard time, get some golf swing aids to help you out.