The way I learned design patterns is by writing lots of really terrible software. When I was about 12, I have no idea what was good or bad. I just wrote piles of spaghetti code. Over the next 10 years or so, I learned from my mistakes. I discovered what worked and what didn't. I independently invented most of the common design patterns, so when I first heard what design patterns were, I was very excited to learn about them, then very disappointed that it was just a collection of names for things that I already knew intuitively. (that joke about teaching yourself C++ in 10 years isn't actually a joke)
Moral of the story: write lots of code. As others have said, practice, practice, practice. I think until you understand why your current design is bad and go looking for a better way, you won't have a good idea of where to apply various design patterns. Design pattern books should be providing you a refined solution and a common terminology to discuss it with other developers, not a paste-in solution to a problem you don't understand.
