On top of anonymous bookmarks (F11 to toggle between activate/deactivate, Shift-F11 to manage), IntelliJ IDEA provides so called numbered bookmarks. What this mean is that on any line of any file managed by IntelliJ IDEA (Java, HTML, XML, JDK source files, etc.), you can define a bookmark that is identified by a number between 0 and 9. Simply put the caret on the desired line and press Ctrl-Shift-<Number> to toggle between activate/deactivate the numbered bookmark. You can then jump to such a numbered bookmark from anywhere within IntelliJ IDEA by triggering Ctrl-<Number>.
For example, place the caret at a point of interest in a Java method and press Ctrl-Shift-1. The gutter to the left will then show a tag labeled with the number 1. You can now jump to this bookmark from anywhere within IntelliJ IDEA by pressing Ctrl-1.
Personally, I find numbered boomarks very handy when working on a specific task where I have to jump back and forth between certain code locations repeatedly. It takes one keystroke to create the numbered bookmark and it takes one keystroke to jump to such a numbered bookmark. It couldn’t be any more efficient.