Best meditative object for people with calm minds?

[An young being]

By my understanding, progress in meditation works differently for different people. Most people advice focusing on the breath in the noise, in the belly etc. Some people advice visualising an object in mind. And some people advice not to focus intenselyat anything at all, just observing thoughts coming to the mind. I have a calm mind, not filled with much thoughts. Which technique might work best for faster progression for people with calmer minds?