General ways to learn more and get better in applications developpement

I am a graduating student from an engineering school (should be equivalent to the master's degree) of computer science.

As you know, in school we learn the basics of a lot of things but we don't learn to master them all.

So I am posting this question to ask you for some advise that I should follow in order to get better at creating applications, learning good programming languages and master some of them. Thank you very much guys !