The most important parts of getting good is lots of practice and the ability to tell good results from bad ones. All professionals gets roughly equal amounts of

The most important parts of getting good is lots of practice and the ability to tell good results from bad ones. All professionals gets roughly equal amounts of practice so there is no use competing on that front. Therefore the only reasonable thing to do is to practice judging things. You want to get better at designing API's? Then start writing down comprehensive critique for as many API's as you can. List good and bad traits and explain your reasoning. This will build understanding about the parts needed for an API to be good. When you are done then you should apply your newfound judgement on projects over and over again since good judgement is nothing without practice.