The old saying

There are a few saying in magic. "Never repeat a trick!" and "Don't announce what you are about to do!"

Honestly those are beginner's tips. The reasons why you should not repeat a trick is that people would know what to expect and be on the look out for things that would expose the method. Same goes for rule number two.

But what if the trick can withstand a repeat? Be it because of changing methods, or because the method is so darn good, that nobody will figure it out? After all, a good old ambitious card is nothing but repeating the trick. In fact repetition makes the effect stronger.

Not announcing what you are about to do also has the built in assumption that magic should come as a surprise. Well suspense is the exact opposite and it is darn good. Try combining the two for maximum impact. If you do the cups and balls, try showing one of the final loads before you start the trick. Even say, that you will try to sneak that lemon under one of the cups near the end of the trick.
That way you build up a lot of suspense. Yet the surprise will still be there after revealing that you had four final loads. You get the best of both worlds, if you announce what you are about to do.

Another saying in magic is the good old: "A large action covers a small action" and too many magician seem to believe that. A little too much. So that they rely on that fact and believe something they do is convincing. That being said...