Often you at least have some intuition or assumption on sth and then you just keep doing experiments to either confirm or falsify this. When sth does not work yet, you do experiments or analysis to better understand why it is failing. And then you try out more ideas to compensate those problems.
There is really no ending here, you can push it further and further as much as you like. You will get a better understanding along the way on what is possible and what is not.
Often you at least have some intuition or assumption on sth and then you just keep doing experiments to either confirm or falsify this. When sth does not work yet, you do experiments or analysis to better understand why it is failing. And then you try out more ideas to compensate those problems.
There is really no ending here, you can push it further and further as much as you like. You will get a better understanding along the way on what is possible and what is not.