What is the safest and most profitable form of trading?
I wouldn't normally use “safe” and “trading” in the same sentence.
Buy and hold works best for very long timeframes of 15 yrs+. If your time horizon is that long, that may work for you.
My current swing strategy is known as “trend following” and works in up/down/sideways markets.
You really need to find a strategy that fits your personality best. If you dislike being in front of a computer monitor all day, then Trend Following (not day trading) may be your thing.