In addition to the great answers here that are specific to note-taking techniques, nothing can replace that, I have also used tools to compliment effective techniques.
Regarding this statement:
I am a trainee and recording minutes during meeting hours creates bad impression because they may think I'm neglecting them.
If you are the "dedicated note taker", I'd bet this is expected and wouldn't worry about it.
For my situation where I wasn't the note taker, but rather someone just taking notes that everyone would happen to reference, my solution was recording audio, specifically Livescribe. It records the audio of the meeting and syncs it with the notes you're taking. In this way, you have the entire meeting to reference, and can just make a note of something important making it very easy to find later.
You could also just use a regular audio recorder and take physical notes at a later time.
I starting doing this because in the beginning of my career, my meetings would often entail highly technical discussions with engineers that were way over my head. Using this method, I could go back and study the conversation later and be magically smarter the next time we spoke. Now that I'm more familiar with the field (and the jargon), I don't really use it.
- It's expensive (specifically Livescrive)
I found it a good investment for me at the time because I also used it for other contexts, like my classes.
- Make absolutely sure you ask permission to record the audio.
Every time I wanted to record, I would ask "Do you mind if I record our discussion for me to reference later?". Usually everyone was fine with it, however I worked on an open source project, so people were very transparent.
- Not everyone will comfortable with it, especially for one-on-one meetings.
It's definitely not always the best solution for every context, so your mileage may vary. Especially since you're a trainee, people may not "trust" you yet. But, this may be more helpful in the future as your responsibilities grow.