A phrase is a riddle that unfolds. So how to build it? How about folding a pattern in on itself much like a fractal. Using what you already have to make more. Music is less about throwing a million ideas at someone, and more about developing a single idea in a multitude of ways. An interesting phrase often has a twist. Before you can throw in the twist though, you must establish the basis for the twist. The first half is about establishing the idea. The third quarter is perhaps the best place for the twist to occur. The end is where the idea resolves. If you haven't noticed this is almost exactly how most movies/plays go->food for thought. It is also the rhythm changes form-AABA. A good phrase/statement will bend your/the listeners ear. Phrasing is NOT WHAT your saying, BUT HOW your piecing it together.