I want to document my code that there is minimum need for reading and browsing code again in months later.

I know that there are different type of documentation (in source code and out of that, sequence diagrams and ...).

Just want to know what is efficient way for documenting my code when few month later I want to see my code, spend fewer time on reading code and understanding code flow.

I want to document my code such that there is minimum need for reading and browsing the code again months later.

I know that there are different types of documentation (in source code and outside, sequence diagrams, and so on).

I just want to know what is an efficient way to document my code so that, when a few months later I want to see my code, I spend less time on reading code and understanding code flow.