According to different situation, you have many choices. when you face a stranger, you'd better say: 过奖了。 but if the person who compliments you is your buddy, you can feel free to respond:呵呵，凑合。 You must pay special attention when you receive compliments from the senior or your boss, I suggest you reply:还要继续努力。 In a word, you can't use one expression to handle various situation. Flexible and appropriate responses can be accumulated in daily life!