How to deal with a 1-year old child who is overly sensitive? She cries so hard even if you just say NO to her wants in a calm tone of voice.

My daughter is at the same stage now. She cries so hard and loud but I have to be firm that our no is a no. Sometimes I distract her with toys, sometimes I just let her cry a bit (especially at home). I noticed lately that she's starting to manipulate us (cry) to get the things that she want so we need to be firm.