When they ask me how you did that,I say I did it very nicely!

interesting, I like it too! and wthe thing with: I will do it with coins instead and :" you don't expect me revealing my secret to you" is very good too I think. thank you very much!

When they ask you to do it again you can sometimes use it as a segue into another trick by saying, "I don't want to do the exact same thing over again, but let's take it one step further." Of course your act has to be structured so there is a logical progression to your effects, which isn't a bad idea anyway. You can use their interest in the previous trick to direct their attention to the next one.