I actually only look for the macro drivers first. ie: the commodity or product/service. I'd have already worked out the best value plays but if the driver/s behind why these stocks/sector will move is strong enough, then I don't really wait for the individual stocks to all be moving to enter..that's only me though, I don't wait till the stocks confirm the trend, and sometimes it happens so quickly, you need to be prepared a bit earlier. Often there is a lag (some time) before the herd/ liquidity arrives.
I think the shell sector is a great recent example of not getting stuck when the headwinds appear.
I often just take a pilot trade in a few if TA looks good, even if sector hasn't confirmed, as you want to try anticipate, well, I do anyway as find it far more rewarding and profitable as long as your timing is ok.
Eg. Zinc, I am not convinced yet, but I took a pilot on IBG after the double bottom just so I keep looking at Zinc stocks and pricing. It's way off it's high on last run, and have only tied up $5k so far...you don't want $ sitting in them just waiting for the theme/sector to get hot.
Like Oil, I only have one stock, KAR, and I'm not convinced at $57 there is a lot in it. KAR just got way oversold, so I'm not really that bullish on oil being a hot sector. it needs to be under a lot more pressure. I'd go in hard like 2014 when everyone on here at under $40 was commenting it would or could go to $20 or even $10! due to Lithium/EV vehicles.or a big theme change in pricing because of the LNG plants - like East Coast Gas was...and some coal seam gas companies got second wind.
I am having trouble seeing a really hot sector with lots of great macros or tailwinds appearing. Nothing looks clear apart from AUD Gold in early DEC. But that's a commodity and can be short lived.
As a longer theme, I think Health-tech/Biotech is still one of the best for next decade.