Sometimes I am offered something but because I'm just a beginner I don't know what verb they used.
I know the proper way to say "no" is to answer with the negative form of the verb the other person used, that いいえ alone is too abrupt.
Also from experience I know that the words in some languages meaning "want" or "need" might have nuances that make them inappropriate.
Usually I want to say "I don't need it" or "I don't want one" in a shop that offers me a bag or a drinking straw or disposable chopsticks. But this evening while exploring Naha I discovered I had wandered into the red light district and was offered a "nice girl"!
How should I correctly express "no thanks, I don't want one" when I didn't hear the verb used?