How can I master multi-timeframe analysis, such as the 15-minute, 1-hour, and 4-hour timeframes?
It’s what a lot of this book is about, and I recommend it (in preference to online information, and particularly in preference to Youtube and forum “information”) as a really good starting-point.
These are actually too far away for multi time frame analysis. You should be looking for closer time frames for example, 5m, 15m and 1 h
Personally I use the M5 and M30 time frames. I would recommend you check out Alex Elder as he has a method for it.