Using the custom fields module, you can define the exact parameters of your products. Those are like sizes, colors, height, numbers of pills for examples or numbers of red roses. It's defense of you, what exactly you want to show the client to order.
The best part is that you can use them for many other things, and they are universal For example, you can create forms with fields and use them for your needs. There is a different type avaliable now like: Text field, Numbers type, Price, Checkbox, Dropdown, Radio Buttons, upload files and more.