My Top 7 Most Underrated IntelliJ IDEA Features
After many years I still meet new people amused when they find out about these features

1. Find anything
It's hard to remember every key combination and track everything that IntelliJ IDEA can do. That’s why I often “Google” inside IntelliJ IDEA. It helps me to find the right menu options, tools, settings and even files in one place.

2. Know where you are
Before I found this feature I was using the “Select Opened File” button to show the currently edited file in my project tree.

Now IntelliJ IDEA does it for me. This is not the default option so you would need to set it for every new or existing project.

3. SQL optimization
Did you know that the default database plugin in your IDE is more than an SQL executor? Given a fact that a persistence layer (Input/Output) is always the slowest part of an application, I always make sure that my SQL queries have a good Execution Plan when working with Relational Databases.

4. Multiline editing
You might have used it in Sublime Text Editor before but you don't have to anymore.

Honestly, I am using only multiline editing but there are lots more. If you are interested, go ahead and check the following article.
5. Go Back / Forward
I really often navigate to the place I was before by clicking the ‘back’ or ‘forward’ buttons

To open recent files press ⌘E (Ctrl+E for Win/Linux))
6. Bookmark
I bookmark important parts of code to quickly jump to them at any point in time.

To go to bookmark press ⌃+<number> (Ctrl+<number> for Win/Linux).
I need to say that I am not using more than 3 bookmarks at the same time as then it becomes hard to remember what are they for.
7. One editor for all
I used to open other Text Editors like Visual Studio Code or Sublime to save parts of the code, JSON, XML etc. to refer it after. It was something that is not really part of the code base (project) and IntelliJ IDEA clearly states it when you try to create or edit something like this. Then I saw one of my colleagues using Snippets and realized how brilliant it is.

Snippets are available and synced across all your projects' windows. I often use it to format some JSONs or SQLs that I got from somewhere else to look closer to it.
My secret recipe
Even now IntelliJ IDE gets lots of updates regularly so usually, it’s hard to keep up with that temp. That is why I would highly recommend reading this sort of article from time to time learning something handy from other specialists in a field.
A cherry on the cake for you and one more feature that saves me tons of time typing every day would be:
Tabnine — Intelijii IDEA code complition plugin based on AI
Right now, it’s free for a decent amount of time per month with no subscription in front but hurry up I don't think it would be for long.
Brill! You are a real curious reader if you got to this point. Now give yourself a pat on the back and see you in the next round.