How to get better at blitz?

#2 Disagree. Fischer simply didn't like blitz. To get better at blitz, you play blitz tbh. Sure they all connect, I have rarely played any classical, or blitz, only bullet all my chess career, mostly only 30 second. I am not "good" because frankly I think you have to start under the age of 10 if you want that.

1.Review at least 10-20% of games with Stockfish ( learn from your mistakes)
2. Puzzles( solve puzzles created by Stockfish)

There are other stuffs but these two help me a lot.