System design interview preparation ideas

Going to start prepping for system design interview. Here's my general plan

1. First get a basic understanding on how to start answering the interview question
2. Try to answer Grokking the System Design interview samples based on the formula I derive from #1.
3. Look at Grokking answer to see improvement areas.

Along with that, will do some reading on DDIA

For experienced people who recently nailed top companies, how does the plan sound? What resource I can check for #1. Also, feel free to provide alternative suggestion.