Maybe you will clean your home many times at one day, you still can smell many bad smells. In fact, no matter how many times you clean, as long as there are people living in the house, these smells will not be so easy to remove.
At first, kitchen odors! 
Trash odors, maybe you think this is trash odors and it’s the trash can itself. You can use baking soda to clean it, and put a  deodorizing pack .

Refrigerator odors,sometimes you eat some bad smells food at home, when it left you will put them in refrigerator. Then you will smell worse smells, right? Now you can put some baking soda in refrigeraror to absorb odors.

Microwave odors, you must put many food in it, such as soups, leftovers and so on. It will left may types of odors in it. You can use hot lemon squash to wipe it and leave the door of the microwave open for a while.

Then bathroom odors.
Worst smells–toilet! Put some cleaning agent, and clean it with a brush, then put some bleach.